All Known (as of June 2012) Planets to Scale (drawn by xkcd)

http://xkcd.com/1071/

http://www.planetary.org/blogs/mat-kaplan/20120620-xkcd-all_exoplanets.html

Exoplanet Study Suggests our Solar System is the Norm

Astrobiology Magazine

Exoplanet Study Suggests our Solar System is the Norm
Source: Centro de Astrofisica da Universidade do Porto press release

Cosmic Evolution  Posted:   04/14/12

Summary: A new study reveals that planetary orbits around Sun-like stars have a tendency to be strongly aligned, similar to the disk-like alignment of the planets in our own solar system.

 

Exoplanets with non-coplanar orbits.
Credit: Ricardo Reis, Centro de Astrofísica da Universidade do Porto

Recently, the HARPS spectrograph and the Kepler satellite made a census of the planetary population around stars like our own, revealing a bounty of planetary systems. A follow-up study lead by members of the EXOEarths team (Centro de Astrofísica da Universidade do Porto -- CAUP), in collaboration with Geneva University, did a joint analysis of the data which showed that the planetary orbits in a system are strongly aligned, like in a disk, just as we have in our own solar system.

The two most effective methods for detecting extrasolar planets are the radial-velocity method and the transit method. The radial-velocity method detects planets through the reflex motion induced by the planet on the star’s velocity on the radial direction (hence the name). This velocity variation is detected through the Doppler effect, the same that leads to a pitch change in the sound of an traveling ambulance. On the other hand, a planetary transit is akin to a mini-eclipse. As a planet travels around the star, its orbit can locate it in front of the star, and the light we collect from the star is reduced because the planet blocks part of it (even though we cannot image the planet).

Astrobiology Magazine

Kepler Confirms ExoPlanet in a Habitable Zone

An exciting development - a Earth-like planet in a habitable zone (even possible that it has Earth-like temperatures). I am sure this planet will be the target of many investigations, especially as newer, more sensitive, equipment come on line.

This artist's conception illustrates Kepler-22b, a planet known to comfortably circle in the habitable zone of a sun-like star. Image Credit: NASA/Ames/JPL-Caltech

NASA's Kepler mission has confirmed its first planet in the "habitable zone," the region where liquid water could exist on a planet’s surface. Kepler also has discovered more than 1,000 new planet candidates, nearly doubling its previously known count. Ten of these candidates are near-Earth-size and orbit in the habitable zone of their host star. Candidates require follow-up observations to verify they are actual planets.

The newly confirmed planet, Kepler-22b, is the smallest yet found to orbit in the middle of the habitable zone of a star similar to our sun. The planet is about 2.4 times the radius of Earth. Scientists don't yet know if Kepler-22b has a predominantly rocky, gaseous or liquid composition, but its discovery is a step closer to finding Earth-like planets.

Previous research hinted at the existence of near-Earth-size planets in habitable zones, but clear confirmation proved elusive. Two other small planets orbiting stars smaller and cooler than our sun recently were confirmed on the very edges of the habitable zone, with orbits more closely resembling those of Venus and Mars.

Read more of this NASA press release at: <http://astrobio.net/pressrelease/4381/kepler-confirms-exoplanet-in-a-habitable-zone>.

Youngest Planet Seen As It’s Forming

Kamuela, HI – The first direct image of a planet in the process of forming around its star has been captured by astronomers who combined the power of the 10-meter Keck telescopes with a bit of optical sleight of hand.

What astronomers are calling LkCa 15 b, looks like a hot “protoplanet” surrounded by a swath of cooler dust and gas, which is falling into the still-forming planet. Images have revealed that the forming planet sits inside a wide gap between the young parent star and an outer disk of dust.

“LkCa 15 b is the youngest planet ever found, about 5 times younger than the previous record holder,” said astronomer Adam Kraus of the University of Hawaii’s Institute for Astronomy. “This young gas giant is being built out of the dust and gas. In the past, you couldn’t measure this kind of phenomenon because it’s happening so close to the star. But, for the first time, we’ve been able to directly measure the planet itself as well as the dusty matter around it.”

Kraus will be presenting the discovery at an Oct. 19 meeting at NASA’s Goddard Space Flight Center. The meeting follows the acceptance of a research paper on the discovery by Kraus and Michael Ireland (of Macquarie University and the Australian Astronomical Observatory), in The Astrophysical Journal (available at http://arxiv.org/abs/1110.3808)

Figure 1 Left: The transitional disk around the star LkCa15. All of the light at this wavelength is emitted by cold dust in the disk. the hole in the center indicates an inner gap with radius of about 55 times the distance from the Earth to the Sun. Right: An expanded view of the central part of the cleared region, showing a composite of two reconstructed images (blue: 2.1 microns, from November 2010; red: 3.7 microns) for LkCa 15. The location of the central star is also marked.

The optical sleight of hand used by the astronomers is to combine the power of Keck’s Adaptive Optics with a technique called aperture mask interferometry. The former is the use of a deformable mirror to rapidly correct for atmospheric distortions to starlight. The latter involves placing a small mask with several holes in the path of the light collected and concentrated by a giant telescope. With that, the scientists can manipulate the light waves.

“It’s like we have an array of small mirrors,” said Kraus. “We can manipulate the light and cancel out distortions.” The technique allows the astronomers to cancel out the bright light of stars. They can then resolve disks of dust around stars and see gaps in the dusty layers where protoplanets may be hiding.

“Interferometry has actually been around since the 1800’s, but through the use of adaptive optics has only been able to reach nearby young suns for about the last 7 years.” said Dr. Ireland. “Since then we’ve been trying to push the technique to its limits using the biggest telescopes in the world, especially Keck.”

The discovery of LkCa 15 b began as a survey of 150 young dusty stars in star forming regions. That led to the more concentrated study of a dozen stars.

“LkCa 15 was only our second target, and we immediately knew we were seeing something new,” said Kraus. “We could see a faint point source near the star, so thinking it might be a Jupiter-like planet we went back a year later to get more data.”

Figure 2 The location of LkCa 15 can be found using this chart.

In further investigations at varying wavelengths, the astronomers were intrigued to discover that the phenomenon was more complex than a single companion object.

“We realized we had uncovered a super Jupiter-sized gas planet, but that we could also measure the dust and gas surrounding it. We’d found a planet, perhaps even a future solar system at its very beginning” said Kraus.

Drs. Kraus and Ireland plan to continue their observations of LkCa 15 and other nearby young stars in their efforts to construct a clearer picture of how planets and solar systems form.

# # #

The W. M. Keck Observatory operates two 10-meter optical/infrared telescopes on the summit of Mauna Kea on the Big Island of Hawaii. The twin telescopes feature a suite of advanced instruments including imagers, multi-object spectrographs, high-resolution spectrographs, integral-field spectroscopy and a world-leading laser guide star adaptive optics system which cancels out much of the interference caused by Earth’s turbulent atmosphere. The Observatory is a private 501(c) 3 non-profit organization and a scientific partnership of the California Institute of Technology, the University of California and NASA.

Source: "Youngest Planet Seen As It's Forming." W. M. Keck Observatory. 2011. Web. 19 Oct. 2011. <http://www.keckobservatory.org/news/first_close-up_view_of_a_planet_being_formed/>

Why explore space?

We will go back to the moon. We will send humans to Mars. We will explore asteroids. We will continue the search for exoplanets, especially for those capable of harboring life. Human beings, generally speaking, are explorers. Holed up, static, we deteriorate. Pushing boundaries, dynamic, we innovate. How many great spin-offs from space exploration do we enjoy in our daily lives? How many important spin-offs from space exploration has extended or saved lives? Going back to the Moon, going to Mars, and out beyond, as well as searching for exoplanets, will make breakthrough discoveries that better serve mankind.

Exploring space is an endeavor that brings peoples together. It is an endeavor that benefits our economies. It is an endeavor that lifts our spirits, excites our imaginations, stirs our souls. It is worshiping the works of God. Humans will return to the Moon, go to Mars, explore the moons of Jupiter and Saturn, and discover new worlds outside our solar system (even if we can only explore them passively from afar). We will do it with robots, small and large; we will do it with astronauts; and to some extent we will do it even, later on, with citizen explorers. We need to look outward from ourselves, and look back to see ourselves in perspective. We will As T.S. Eliot wrote in his poem “Little Gidding”:

And the end of all our exploring
Will be to arrive where we started
And know the place for the first time.

We need to explore, to learn. Moon –> Mars –> and Beyond.

Exoplanet indifference?

It is interesting how quickly humans can adapt to an environment. When Apollo 13 was heading to the Moon, and before the explosion that almost cost the lives of the astronauts on board, the public was already feeling familiar with Moon shots. It was no longer front page news, no longer worthy of extended TV coverage - in fact, it barely got covered at all, by comparison to Apollo's 11 and 12. The explosion changed all of that of course.

Has the search for exoplanets already begun to become familiar? Over 400 exoplanets have been discovered. When more are announced, it's almost met with a "Oh, isn't that nice. Honey, will you pass the salt? Hey, I hear it will rain tomorrow..."

Though what is helping to maintain some excitement is that the exoplanet search keeps getting more sophisticated and refined and finding smaller and smaller planets. We are even beginning to detect, even if just barely, the atmospheres of planets orbiting alien suns hundreds of light years away. Each new telescope that joins the hunt breathes in fresh life, and new excitement, into the search.

Rest assured that when a truly Earth-like terrestrial planet is discovered (an Earth-sized, or nearly so, terrestrial planet orbiting a stable star in the HZ), it will be an "explosive" discovery that will thrust the search for exoplanets back into the spotlight, especially if an atmosphere is detected and gives initial signs of being habitable (though even a good spectral analysis of an atmosphere probably can not prove the existence of life on the planet).

If We Are Alone

It's Full of Planets!

Over 400 exoplanets discovered so far. Finding more expolantes is almost becoming normal - and its not just "hot Jupiters" that are being found. Increasingly, as our techniques and equipment improve and more telescopes are brought online to join the hunt, smaller terrestrial planets are being found. Everywhere we look, it seems, we find planets. It is looking like the universe is full of planets.

Think abut that. Full of planets. Maybe in 2001: A Space Odyssey astronaut David Bowman should've exclaimed "The thing's hollow—it goes on forever—and—oh my God—it's full of planets!"

Apply the Drake Equation, and it's looking like the universe is also full of life, including intelligent life.

However...

This does not automatically mean we are not alone. If the universe is infinite, and life arose in one spot of it, it does seem incredibly unlikely we would be the only ones. Even if the universe is not infinite - it still contains at least 100 billion galaxies, each with many stars (our own contains an estimated 100 billion stars), many of which may contain planets. The number of possible planets is astounding. However, while it may seem rather implausible, just because the universe may be populated with planets is not a Q.E.D. proof that we are not alone, despite, as Jodi Foster's character in the movie Contact propositions, that "if we are the only ones, it would be an awful waste of space, wouldn't it?"

If We Are Alone

What would that mean, if we were alone? That we are given, or by chance have, all this space in which to  explore, expand, and evolve in? If we are given all of the immense space filled with stars and planets, but no other life - what is the purpose of that gift? What are our responsibilities? Should we go forth, multiply and replenish not only the Earth but the universe? Or should we leave other planets alone and not contaminate them with Earth probes and the Earth microbes that may be on them?

And does it even have to have a meaning? The universe does not know it is immense, or teeming with planets. A star does not know that it exists. It does not feel itself traveling through space, circled by planets. Gravity acts upon it without it knowing that anything at all is happening. A planet does not know that it is barren, or that it has life on it. It is barren, or life-filled, only to us (if any of this has an echo of familiarity to it, it may be because you've read Nobel Prize winning Polish poet Wislawa Szymborska's thought provoking poem "View with a Grain of Sand"). Meaning is arbitrary, maybe illusory.

What is Meant

But even if that meaning is arbitrary, and only has meaning to us - that may be enough. It may be up to us to give beauty to the universe, to create meaning, even if it is only for our benefit, our pleasure, our peace of mind.

I have no answers. I would be stunned if there were no other life forms outside the Earth. But, I also realize that true absolutes rarely exist, and to say it is impossible is wrong. It may be astronomically (if you'll excuse the pun) improbable, but not impossible.

What do you think?


Image Credits: 1. Warner Bros. 2. Chris Butler.

32 New Exoplanets Found

Exciting news. The following video announces the discovery of 32 additional exoplanets (bringing the total discovered to over 400 to date), and shows how such discoveries are made using ESO's HARPS (High Accuracy Radial Velocity Planet Searcher).

19 October 2009
For immediate release

32 New Exoplanets Found

Today, at an international ESO/CAUP exoplanet conference in Porto, the team who built the High Accuracy Radial Velocity Planet Searcher, better known as HARPS, the spectrograph for ESO's 3.6-metre telescope, reports on the incredible discovery of some 32 new exoplanets, cementing HARPS's position as the world’s foremost exoplanet hunter. This result also increases the n umber of known low-mass planets by an impressive 30%. Over the past five years HARPS has spotted more than 75 of the roughly 400 or so exoplanets now known.

"HARPS is a unique, extremely high precision instrument that is ideal for discovering alien worlds," says Stéphane Udry, who made the announcement. “We have now completed our initial five-year programme, which has succeeded well beyond our expectations.”

The latest batch of exoplanets announced today comprises no less than 32 new discoveries. Including these new results, data from HARPS have led to the discovery of more than 75 exoplanets in 30 different planetary systems. In particular, thanks to its amazing precision, the search for small planets, those with a mass of a few times that of the Earth — known as super-Earths and Neptune-like planets — has been given a dramatic boost. HARPS has facilitated the discovery of 24 of the 28 planets known with masses below 20 Earth masses . As with the previously detected super-Earths, most of the new low-mass candidates reside in multi-planet systems, with up to five planets per system.

Read more of the ESO Science News release at <http://www.eso.org/public/outreach/press-rel/pr-2009/pr-39-09.html>.

You Can Help Find Exo-Earths

From The Planetary Society, a way that laypersons can get involved in the search for terrestrial exoplanets:

FINDS Exo-Earths

A thrilling new hunt for Earth-like planets orbiting distant stars is starting...

The Planetary Society is teaming up with planet hunters Geoff Marcy of the University of California at Berkeley and Debra Fischer of San Francisco State University to help with the quest to find other "Earths," other worlds like our own, elsewhere in our galaxy.

The project is called FINDS Exo-Earths (which stands for Fiber-optic Improved Next generation Doppler Search for Exo-Earths).

This new high-end optical system will be installed on the 3-meter telescope at the Lick Observatory, dramatically increasing discoveries of smaller exoplanets and playing a crucial role in verifying Earth-sized planet candidates from the Kepler planet-hunter mission.

This is exactly the kind of project the Society has always excelled at. It's a small, vital effort, overlooked and under-valued by the space community's "Powers That Be." And we can see that it offers an incredible cost-benefit ratio.

Imagine: a way to specifically hunt for and discover Earth-sized planets orbiting far distant suns. This could truly revolutionize exoplanet exploration. It will, at the very least, massively expand our scientific knowledge; at best, it could eventually prove a major step forward in the dream of finding life native to another world. It will also provide valuable backing to NASA's Kepler mission, a vital goal all in itself.

How Does FINDS Exo-Earths Work?

When planet hunters train their telescopes on the stars, they usually aren't looking for an actual visual image of any planets. The distances are simply too vast. Rather, they seek evidence of those distant planets based on the behavior of the light from the stars themselves.

The most common method is called the "radial velocity technique," which relies on measuring minute Doppler effect changes in the star's light. The starlight changes because orbiting planets "tug" on their stars; so, as they circle, a minute Doppler effect occurs in the starlight. This tug either pulls the light waves slightly apart, or pushes them slightly together, changing their frequency. (It's the same effect that occurs to sound waves when a train rushes by you, with the sound of its whistle suddenly dropping in pitch.)

You can imagine how small these changes are, and how hard to detect. Modern technologies make it possible, but there are limits. For example, the terrific 3-meter telescope at the Lick Observatory can detect Doppler velocities of about 5 meters per second. That's good enough to spot enormous Jupiter-sized planets.

But to identify smaller worlds -- the ones more likely to have life -- a telescope must be able to detect Doppler velocities of 1 meter per second. To detect a planet the size and density of Earth, the precision would have to be under 0.5 meters per second.

The Marcy-Fischer team has tackled this problem by devising not one, but two optical systems to be used in tandem. The first is a fiber optics array that will make the cone of light entering the telescope's spectrometer "uniform," and therefore resilient to naturally occurring changes that foul up Doppler measurements.

The second part is an adaptive optics system that will keep the maximum amount of light flowing through the system -- that is, providing a better "signal-to-noise ratio."

Altogether, this bundle of new technology is referred to as Fiber-optic Improved Next generation Doppler Search for Exo-Earths, or FINDS. At Lick, it could improve detection to the 1-meter range, enabling additional discovery of many Neptune-sized planets and larger. If Marcy-Fischer can do all that with our help, then it will be on to the Keck Telescope, where 0.5 meter precision (and Earth-size planet discoveries) can happen.

And, once our instrument is adapted for the Keck Telescope, FINDS Exo-Earths will provide crucial follow-up for planets found by the Kepler mission. Specifically, the Keck Telescope -- equipped with FINDS -- will rule out false positive detections of Earth-sized worlds.

We're on the brink of discovering Earth-like planets around other stars -- worlds that may support life. You can play a key role in the hunt!

To make a secure tax-deductible donation to the FINDS Exo-Earths project, visit the Project's donation Web page at <https://planetary.org/join/donate/0903exow/>. The Planetary Society's FINDS Exo-Earths Project main Web page is at <http://planetary.org/programs/projects/finds/>.


Reference:

"Projects: FINDS Exo-Earths." What We Do. The Planetary Society. n.d. Web. 19 September 2009. <http://planetary.org/programs/projects/finds/>

Image credit: Ryan Bliss, DigitalBlasphemy

First Solid Evidence for a Rocky Exoplanet!

The following is a breaking news release from the European Space Organization:

ESO 33/09 - Science Release

16 September 2009
For immediate release

First Solid Evidence for a Rocky Exoplanet

Mass and density of smallest exoplanet finally measured

The longest set of HARPS measurements ever made has firmly established the nature of the smallest and fastest-orbiting exoplanet known, CoRoT-7b, revealing its mass as five times that of Earth's. Combined with CoRoT-7b's known radius, which is less than twice that of our terrestrial home, this tells us that the exoplanet's density is quite similar to the Earth's, suggesting a solid, rocky world. The extensive dataset also reveals the presence of another so-called super-Earth in this alien solar system.

"This is science at its thrilling and amazing best," says Didier Queloz, leader of the team that made the observations. "We did everything we could to learn what the object discovered by the CoRoT satellite looks like and we found a unique system."

In February 2009, the discovery by the CoRoT satellite [1] of a small exoplanet around a rather unremarkable star named TYC 4799-1733-1 was announced one year after its detection and after several months of painstaking measurements with many telescopes on the ground, including several from ESO. The star, now known as CoRoT-7, is located towards the constellation of Monoceros (the Unicorn) at a distance of about 500 light-years. Slightly smaller and cooler than our Sun, CoRoT-7 is also thought to be younger, with an age of about 1.5 billion years.

Every 20.4 hours, the planet eclipses a small fraction of the light of the star for a little over one hour by one part in 3000 [2]. This planet, designated CoRoT-7b, is only 2.5 million kilometres away from its host star, or 23 times closer than Mercury is to the Sun. It has a radius that is about 80% greater than the Earth's.

The initial set of measurements, however, could not provide the mass of the exoplanet. Such a result requires extremely precise measurements of the velocity of the star, which is pulled a tiny amount by the gravitational tug of the orbiting exoplanet. The problem with CoRoT-7b is that these tiny signals are blurred by stellar activity in the form of "starspots" (just like sunspots on our Sun), which are cooler regions on the surface of the star. Therefore, the main signal is linked to the rotation of the star, with makes one complete revolution in about 23 days.

To get an answer, astronomers had to call upon the best exoplanet-hunting device in the world, the High Accuracy Radial velocity Planet Searcher (HARPS) spectrograph attached to the ESO 3.6-metre telescope at the La Silla Observatory in Chile.

"Even though HARPS is certainly unbeaten when it comes to detecting small exoplanets, the measurements of CoRoT-7b proved to be so demanding that we had to gather 70 hours of observations on the star," says co-author François Bouchy.

HARPS delivered, allowing the astronomers to tease out the 20.4-hour signal in the data. This figure led them to infer that CoRoT-7b has a mass of about five Earth masses, placing it in rare company as one of the lightest exoplanets yet found.

"Since the planet's orbit is aligned so that we see it crossing the face of its parent star — it is said to be transiting — we can actually measure, and not simply infer, the mass of the exoplanet, which is the smallest that has been precisely measured for an exoplanet [3]," says team member Claire Moutou. "Moreover, as we have both the radius and the mass, we can determine the density and get a better idea of the internal structure of this planet."

With a mass much closer to that of Earth than, for example, ice giant Neptune's 17 Earth masses, CoRoT-7b belongs to the category of "super-Earth" exoplanets. About a dozen of these bodies have been detected, though in the case of CoRoT-7b, this is the first time that the density has been measured for such a small exoplanet. The calculated density is close to Earth's, suggesting that the planet's composition is similarly rocky.

"CoRoT-7b resulted in a 'tour de force' of astronomical measurements. The superb light curves of the space telescope CoRoT gave us the best radius measurement, and HARPS the best mass measurement for an exoplanet. Both were needed to discover a rocky planet with the same density as the Earth," says co-author Artie Hatzes.

CoRoT-7b earns another distinction as the closest known exoplanet to its host star, which also makes it the fastest — it orbits its star at a speed of more than 750 000 kilometres per hour, more than seven times faster than the Earth's motion around the Sun. "In fact, CoRoT-7b is so close that the place may well look like Dante's Inferno, with a probable temperature on its 'day-face' above 2000 degrees and minus 200 degrees on its night face. Theoretical models suggest that the planet may have lava or boiling oceans on its surface. With such extreme conditions this planet is definitively not a place for life to develop," says Queloz.

As a further testament to HARPS' sublime precision, the astronomers found from their dataset that CoRoT-7 hosts another exoplanet slightly further away than CoRoT-7b. Designated CoRoT-7c, it circles its host star in 3 days and 17 hours and has a mass about eight times that of Earth, so it too is classified as a super-Earth. Unlike CoRoT-7b, this sister world does not pass in front of its star as seen from Earth, so astronomers cannot measure its radius and thus its density.

Given these findings, CoRoT-7 stands as the first star known to have a planetary system made of two short period super-Earths with one that transits its host.

Notes

[1] The CoRoT mission is a cooperation between France and its international partners: ESA, Austria, Belgium, Brazil, Germany and Spain.

[2] We see exactly the same effect in our Solar System when Mercury or Venus transits the solar disc, as Venus did on 8 June 2004 (ESO PR 03/04). In the past centuries such events were used to estimate the Sun-Earth distance, with extremely useful implications for astrophysics and celestial mechanics.

[3] Gliese 581e, also discovered with HARPS, has a minimum mass about twice the Earth's mass (see ESO 15/09), but the exact geometry of the orbit is undefined, making its real mass unknown. In the case of CoRoT-7b, as the planet is transiting, the geometry is well defined, allowing the astronomers to measure the mass of the planet precisely.

More Information

This research was presented in a paper to appear in a special issue of the Astronomy and Astrophysics journal on CoRoT, volume 506-1, 22 October 2009: "The CoRoT-7 planetary system: two orbiting Super-Earths", by D. Queloz et al.

The team is composed of D. Queloz, R. Alonso, C. Lovis, M. Mayor, F. Pepe, D. Segransan, and S. Udry (Observatoire de Genève, Switzerland), F. Bouchy, F. and G. Hébrard, G. (IAP, Paris, France), C. Moutou, M. Barbieri, P. Barge, M. Deleuil, L. Jorda, and A. Llebaria (Laboratoire d'Astrophysique de Marseille, France), A. Hatzes, D. Gandolfi, E. Guenther, M. Hartmann, and G. Wuchterl (Thüringer Landessternwarte Tautenburg, Germany), M. Auvergne, A. Baglin, D. Rouan, and J. Schneider (LESIA, CNRS, Observatoire de Paris, France), W. Benz (University of Bern, Switzerland), P. Bordé, A. Léger, and M. Ollivier (IAS, UMR 8617 CNRS, Université Paris-Sud, France), H. Deeg (Instituto de Astrofísica de Canarias, Spain), R. Dvorak (University of Vienna, Austria), A. Erikson and H. Rauer (DLR, Berlin, Germany), S. Ferraz Mello (IAG-Universidade de Sao Paulo, Brazil), M. Fridlund (European Space Agency, ESTEC, The Netherlands), M. Gillon and P. Magain (Université de Liège, Belgium), T. Guillot (Observatoire de la Côte d'Azur, CNRS UMR 6202, Nice France), H. Lammer (Austrian Academy of Sciences), T. Mazeh (Tel Aviv University, Israel), and M. Pätzold (Köln University, Germany).

ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

Links

• Research paper: http://www.aanda.org/10.1051/0004-6361/200913096/pdf (Free access)
• More info: Exoplanet — media kit

Contacts
Didier Queloz
Geneva Observatory, Switzerland
Phone: +41 22 379 2477
E-mail: didier.queloz (at) unige.ch

François Bouchy
IAP, Paris and OHP, St Michel l'Observatoire, France
Phone: 33 4 92 70 64 94
E-mail: bouchy (at) iap.fr

Claire Moutou
Laboratoire d'Astrophysique de Marseille, France
Phone: +33 4 91 05 59 66
E-mail: Claire.Moutou (at) oamp.fr

Artie Hatzes
Thüringer Landessternwarte Tautenburg, Germany
Phone: +49 36 42 78 63 55
Mobile: +49 (0)163 69 13 863
E-mail: artie (at) tls-tautenburg.de

ESO La Silla - Paranal - ELT Press Officer: Henri Boffin - +49 89 3200 6222 - hbofin@eso.org
ESO Press Officer in Chile: Valeria Foncea - +56 2 463 3123 - vfoncea@eso.org
National contacts for the media: http://www.eso.org/public/outreach/eson/

Dante's Inferno

Maybe we should call this planet Dante, it sure is one hellava planet as it shows how detection methods are advancing rapidly and that our galaxy, if not the universe, will be found to be abundantly populated with planets - from gas giants to smaller terrestrials. So while this first confirmed rocky planet is a blast furnace, it is just the first to be found. Improved planet hunting devices are in development which will increase our ability to discover terrestrials. We are still just at the beginning of an exiting search.

Reference:

"First Solid Evidence for a Rocky Exoplanet." Press Releases 2009. ESO for the Public. ESO. 16 Sept. 2009. Web. 16 Sept. 2009. <http://www.eso.org/public/outreach/press-rel/pr-2009/pr-33-09.html>


Image credit: ESO

Wrong Way Planet

Scientists have discovered that WASP-17 is orbiting its star in the opposite direction (retrograde) of its star's spin. Most planets orbit their stars in the same direction of their star's spin. WASP-17 must have had a violent past, such as a near collision early in its life, for it to be in a retrograde orbit. Because of this violent past, it does not have a circular orbit.

This got me to wondering - if, in this possibly infinite universe, there exists a life harboring planet that orbits its star in the wrong direction, and by an extremely rare stroke of luck, orbits its star in a nearly circular orbit (eccentric orbits are not as conducive to life). Would the sentient species that arises, seeing that their planet orbits in the opposite direction from all the other planets in their star system (and later, they discover, around other star systems as well), think that this is a sign that they are special above all others? When they later find life on other planets, and find that those planets orbit with their star, would they think them inferior, or infidels?

Of course maybe they would reason differently than humans. Maybe they would think the opposite. Or have little emotions and thus not really moved one way or the other, other than curiosity as to why their planet is different.

By they way, the planet gets its name for the SuperWASP (Wide Angle Search for Planets) program, not because it is a planet inhabited by hymenopterans, or by white Anglo-Saxon protestants...


References

Alexander, Amir. "Scientists Detect 'Wrong-Way' Planet." Planetary News. The Planetary Society. 12 Aug. 2009. Web. 31 Aug. 2009. <
http://planetary.org/news/2009/0812_Scientists_Detect_WrongWay_Planet.html>

"SuperWASP Homepage." SuperWASP - Wide Angle Search for Planets. 3 June 2009. Web 31 Aug. 2009. <http://www.superwasp.org/>


Image credit: ESA/C. Carreau

The Sun's Twin? (and does that mean another Earth as well?)

Another Sol?

An article by Bob Berman in this month's (Oct 2009) issue of Astronomy mentions that

of the 1,000 nearest stars within 3 dozen light-years, only one matches our Sun's temperature, size, and luminosity and has the same precise spectral class of G2V (a main sequence star with a surface temperature of about 9980 degrees Fahrenheit...).

In addition, that twin star is similar in age, though a bit older: the Sun is 4.6 billion years old, while this twin star is 5 to 6 billion years old.

One in a Thousand

That twin star? Alpha Centauri A. As Bob Berman points out - of all those 1,000 stars the only one that is the Sun's close twin is also the nearest naked-eye star (4.35 light-years away). An amazing coincidence. 

Hopefully the new generation telescopes, especially the whose main tasks are to search for exoplanets, will aim their sights on the Centauri trinary system. It would almost be criminal not to take a closer look. If there is a terrestrial planet circling Alpha Centauri A, the new generation telescopes should be able to find it. With Alpha Centauri A a bit older than the Sun, unless life evolved on Earth quicker than usual, a terrestrial planet in a habitable zone around Alpha Centauri A would have had plenty of time for sentient life to arise.

Long Distance Relationship

Of course, maybe sentient life does not survive its early years of sentience and there is no longer any sentient life to discover... But let us be optimistic for a moment and say that it survives. 4.35 light-years away would allow for communication via radio waves or laser. Sure, it would take 8.7 years for each message to be answered (4.35 years for it to travel there, and 4.35 years for the answer to travel back), but it still could be done.

But should we try to communicate with them? The wonders are tempting, but there is the possibility of danger...


References

"Alpha Centauri - A Candidate for Terrestrial Planets And Intelligent Life." Smoot Group Cosmology. The Smoot Group. 15 Oct. 1997. Web. 30 Aug. 2009. <http://aether.lbl.gov/www/classes/p139/speed/Alpha-Centauri.html>

Berman, Bob. "A dozen cool facts." Strange Universe. Astronomy. Oct 2009: 16. Print.


Image Credit: The Smoot Group.

Google Earth and Exoplanets

Google Earth has a most excellent plug-in for exoplanet fans - a plugin for the sky view that displays the over 200 explanets discovered so far:

<http://services.google.com/earth/kmz/exo_planets_n.kmz>

You'll need to first download Google Earth to use it (version 5.0 at the time of writing this post). If you do not already have Google Earth, you can download it at:

<http://earth.google.com/>

Enjoy!

Another Image of an Exoplanet

Click photo to enlarge. Credit: NASA, ESA, P. Kalas, J. Graham, E. Chiang, E. Kite (University of California, Berkeley), M. Clampin (NASA Goddard Space Flight Center), M. Fitzgerald (Lawrence Livermore National Laboratory), and K. Stapelfeldt and J. Krist (NASA Jet Propulsion Laboratory)

Yet another photo of an exoplanet - this one by the Hubble Space Telescope of a planet circling Fomalhaut 25 light years from Earth in the Piscis Australis constellation.. This is the first visible light photo (the previous photos of planets circling HR 8799 used infrared). The planet, Fomalhaut b, is estimated to less than three times Jupiter's mass and orbiting 10.7 billion miles (roughly 115 AUs) out from Fomalhaut; by comparison Pluto is 39.5 AUs from our Sun. A large dust ring surrounds Fomalhaut, and astronomers theorized that since the ring was offset from the star, with a sharp inner edge - evidence that pointed to a planet circling the star gravitationally affecting the ring. Fomalhaut b is a billion times dimmer than the star is orbits, so the work of finding the planet was demanding, but after several years of determined work, the team of astronomers met with success - the first visible light photo of an exoplanet. The hunt for exoplanets is moving in exciting directions.

Reference:

"Hubble Directly Observes A Planet Orbiting Another Star." Science News. ScienceDaily. 13 Nov. 2008. Web. 21 Nov. 2008. <http://www.sciencedaily.com/releases/2008/11/081113151456.htm>.

First confirmed images of exoplanets

© Credit: Gemini Observatory

Gemini and Keck observatory astronomers, using adaptive optics, have taken the first photos of confirmed exoplanets. Readers may recall the First Picture of an Extrasolar Planet! post Oct 3, also from Gemini Observatory - but that one is yet to be confirmed to be a planet. Three planets were confirmed. The planets in the photo to the right, taken by the Gemini Observatory, are two super Jupiters circling the star HR 8799 located 130 light-years away in the Pegasus constellation. The planets are circling 40 and 70 AUs from the central star. Astronomers at the Keck II Observatory discovered the third planet, circling 25 AUs away. HR 8799 is a very young star about 1.5x the mass of the Sun, and 5x brighter. The planets were probably formed 60 million years ago, far too young for life. But in the future...

© Credit: "Gemini Observatory Artwork by Lynette Cook"

Which raises an interesting thought. Far into the Earth's future, whatever sentient life form is the dominant species at the time, may have to abandon the Earth as the Sun expands and boils away the Earth's atmosphere and oceans. The planet may have to be abandoned - by then if there are any Earth-sized planets or Earth-sized moons circling the gas giants of HR 8799, they will be old enough to be hospitable for life. Future Earthlings may have to abandon this solar system for another. It would be probably easiest to colonize/terraform a planet that is ready for life, but on which life has yet to establish itself or has yet to firmly establish itself. That way the Earthlings can form the planet to their needs. This would, thus, have to begin some time before the Earth needs to be abandoned. 130 light-years is quite a distance away, but for a technologically advanced civilization that is desperate, very desperate, it could be done. Even if it was by robots including robotic ships that carried suspended genetic material to seed not only Earth life, but whoever the sentient life form is (we hope it will still be humans).

References:

"Gemini Releases Historic Discovery Image of Planetary 'First Family.'" Gemni Observatory. 13 Nov. 2008. Web. 20 Nov. 2008. <http://www.gemini.edu/threeplanetspr>.

"First Picture of Likely Planet around Sun-like Star." Gemini Observatory. 15 Sept. 2008. Web. 5 Oct. 2008. <http://www.gemini.edu/node/11126>.

"Planetary First Family Images." Gemini Observatory. 13 Nov. 2008. Web. 20 Nov. 2008. <http://www.gemini.edu/node/11150>.

Possible First Picture of an Extrasolar Planet!

© Gemini Observatory

What you are looking at in the upper left hand corner of the image is quite possibly the first photo of an extrasolar planet. The young hot planet is about eight times the mass of Jupiter, orbiting about 330 A.U.s from the very young (approximately 5 million years old) Sun-like central star 1RXS J160929.1-210524 (located 500 light-years from the Earth). 330 A.U.s is 11 times the distance of Neptune's orbit around our Sun (1 A.U. is the distance of the Earth from the Sun).

Because the young planet is orbiting so far away, it's presence is a challenge to planetary formation theories. This may indicate that there may be more than one means of planetary formation, and that, thus, there will be an even greater variety of solar systems than first thought (which may also mean a greater variety of worlds for life to evolve on).

Next on the agenda is to see if the possible planet is actually gravitationally tied to the star. This will take two years to determine.

The University of Toronto astronomers (David Lafrenière, Ray Jayawardhana, Marten H. van Kerkwijk) who discovered this planetary object using the Gemini North telescope on Mauna Kea in Hawai‘i, viewed the extrasolar system in the near-infrared range using adaptive optics technology to reduce distortions from air turbulence.

The star is a very young K7 type star, 85% the mass of our Sun. Being young and very hot, it is also very large. The planet is also very hot, about 11.25 times hotter (Jupiter is about -110ºC, while this planet is at around 1500 ºC).

Reference:

"First Picture of Likely Planet around Sun-like Star." Gemni Observatory. 15 Sept. 2008. Web. 5 Oct. 2008. <http://www.gemini.edu/node/11126>.

Extrasolar planets simulation site

Stumbled across a most excellent (yes, I watched Bill and Ted's Excellent Adventure) site for those not only interested in the search for extrasolar planets, but would like to help out, even as an amateur: Systemic: characterizing extrasolar planetary systems at <http://oklo.org>. From the "What is Systmeic?" section of their Website:

The near-term goal of the systemic research collaboration is to improve our statistical understanding of the galactic planetary census. This will be accomplished through a large-scale simulation in which the public is invited to participate. No prior experience or expertise with Astronomy is required. All you need is an Internet connection and a desire to learn and explore.

Check it out!

Reference:

Laughlin, Gregg. "What is Systemic?" Systemic: characterizing extrasolar planetary systems. Wordpress. 2 Jan. 2006 Web. 11 Sept. 2008. <http://oklo.org/?page_id=33>

Reflected Light From an Exoplanet Seen

Credit: 2007, ETH Zurich, S.V. Berdyugina

Last December, a team of astronomers with the Zurich's Institute of Astronomy, imaged, for the first time, the reflected light of an exoplanet (known as HD9189733b) using polarization (similar to how Polaroid sunglasses work). Because of this, they were able to, again for the first time, directly determine the orbit of an exoplanet. The planet orbits the dwarf star HD189733 located more than 60 light years away in the constellation Vulpecula. It orbits very close to its parent, with a year measured in just a couple of days. Because this close proximity, HD9189733b's atmosphere is swollen by the heat, as well as brightly reflects the dwarf stars light - which makes it easier to be detected visually.

This is an exciting development; another step toward being able to eventually (though probably not that far away) determine the atmospheric composition of another planet.

It may be that we will first detect extraterrestrial life not by their radio signals, but by visually seeing and analyzing their planet's atmosphere!

Reference:

ETH Zurich/Swiss Federal Institute of Technology. "Exoplanet Reflected Light Detected For The First Time." ScienceDaily. 28 December 2007. 31 March 2008 <http://www.sciencedaily.com/releases/2007/12/071226225432.htm>.

Hypervelocity Stars (updated)

© Ruth Bazinet/Harvard-Smithsonian
Center for Astrophysics

Hypervelocity stars are stars that are moving, on average, around 7x than the average for, well, your average star. OK, in other words the average velocity for most stars is around 223,694 mph, which seems plenty fast but your average hypervelocity star moves at 1,615,068 mph (1.6 million mph)!

What causes these stars to become dragsters? A binary star system tangling with a black hole. If the conditions are right, one of the binary will be captured by the black hole, while the other star gets flung away at great velocity.

Not many of these hypervelocity stars have been found so far. One recent discovery, HE 0437-5439, has not been ejected from the Milky Way, but from the Large Magellanic Cloud (LMC), a small neighbor galaxy. This star is strong indirect proof of a black hole somewhere in the LMC.

What would that mean for any life on a habitable planet around such a star? They would see constellations change about 7 times faster than we do and they would experience a slight relativistic time dilation (1.5 minutes per year).

But most importantly, they would either pass by other stars several times more often than our own Sun, or be flung out into intergalactic space - far from any other star. The latter would be lonely civilizations indeed, unless they could somehow develop faster than light speeds, as it may take a few billion years for sentient life to arise on such a planet; after a few billion years they would be thousands of light years out into intergalactic space by the time they developed a technological civilization. They would be even further out if they had the unfortunate luck of being ejected from the galaxy, or the LMC, in the opposite direction of the galaxy's trajectory (the Local Group of galaxies, of which the Milky Way and the LMC are members of, is moving at 1.34 million miles per hour in the direction of the constellation Hydra) ¹.

There is an additional effect of being flung out into intergalactic space: being so far from other stars would mean the chances of being effected by a nearby supernova would be nearly zero. As mentioned in a previous post, for the Earth, a supernova 30 light years or closer would be quite devastating for life - for other planets, the distance could be greater, depending upon how thick their protective atmospheres are (to show you how protective our atmosphere is, for astronauts outside the Earth's atmosphere, a supernova 3,000 light years away could be deadly). Some scientist conjecture that maybe a supernova was involved in past extinction events on Earth.

In addition, the solar system would not be affected by galactic disturbances (compression waves, for instance). Thus, the system might be more "boring" than our own, and thus allow sentient life to form more rapidly. HE 0437-5439 is a young star, only 35 million years old, so if there are any planets around it (and it is a big if), and if one of those planets is habitable and in the habitable zone, most likely hasn't arisen yet. But if it does, and it evolves into a sentient race, it will be a very isolated race.

Would they feel themselves blessed by being alone in the universe? Will it appear, to them, that the entire universe revolves around them - even the galaxies? Though if their parent galaxy is racing away from them, what would the make of it? Would they instead feel abandoned? Any thing they create would be lost when their star dies - there would be no one else to ever come along to explore their world. Would this affect how they lived? And if so, how?

Of course, if faster than light travel is somehow possible, by some "trick" (like worm holes), maybe they would be more pressured to discover it than would other, galactic, civilizations; and solve their isolation that way.

Another example of counsel given by Hamlet: "There are more things in heaven and earth, Horatio, Than are dreamt of in your philosophy" (Hamlet Act 1, scene 5, 159–167). Speculating on on possible extrasolar (alien) biological, psychological, societal, technological, and theological realities stretches the dreams of any of our philosophies here on Earth!

Notes:

1. A light year is the distance light travels in mph: 186,000 miles/second * 60 seconds/minute * 60 minutes/hour = 669,600,000 mph.

The distance light travels in a year: 186,000 miles/second * 60 seconds/minute * 60 minutes/hour * 24 hours/day * 365 days/year = 5,865,696,000,000 miles/year.

A hypervelocity star traveling at 1,615,000 mph would be traveling at 0.04145 light years per year: 1,615,000 mph/669,600,000 mph = 0.0024119 or 0.24119 % the speed of light.

Thus, the hypervelocity star would cover 0.24119% of 5,865,696,000,000 miles/year; it would take the star 414.611 years to cover a light year.

For a hypervelocity star leaving a galaxy, in 4 billion years it could be (depending upon relative velocity of it with its parent galaxy) 9,647,597.386 light years away from its parent galaxy! If sentient life takes as long to develop on a planet around such a star as it did on Earth (4.5 billion years), it would be 10,853,547.06 light years away.


References:

Kraan-Korteweg, Renée C. & Ofer Lahav. "Galaxies Behind The Milky Way." Scientific America. October 1998.

Przybilla, N. et al. "LMC origin of the hyper-velocity star HE 0437-5439. Beyond the supermassive black hole paradigm." Astrophysical Journal Letters. Submitted on 29 Jan 2008. 17 Feb 2008. <http://arxiv.org/abs/0801.4456>.

"What is a Light Year?" How Stuff Works. 17 February 2008. < http://www.howstuffworks.com/question94.htm>.

Methuselah - Addendum

© John Whatmough

The Methuselah - 13 Billion Yr Old Planet (Garden of Eden?) post has been updated, thanks to a reader's feedback who correctly pointed out that I mislabeled M4 as an open cluster. I also addressed the issue of the low metallic nature of early globular clusters more clearly - early stellar nurseries should not be capable of producing planets, yet here we have at least one that was formed 13 billion years ago. The probability of life forming on that planet is rather low (at least life as we know it) as it is most likely a gaseous planet, but not zero. And it does raise the possibility (this blog is about speculation, after all) that other ancient planets exist - including a smaller terrestrial planet orbiting in the same system as Methuselah which current methods do not allow us to detect. And that raises the possibility, even if a slim one, that life did arise far earlier in the universe than first thought.