Category Archives: Exoplanets

ESA’s Next Science Mission

Funny how things progress. Not that long ago other planetary systems were unknown altogether and now we know they are really common place. We’ve even gotten to the point where we going to be looking at the chemical composition of their atmospheres. That’s one of the goals of Ariel or the Atmospheric Remote‐sensing Infrared Exoplanet Large‐survey mission.

Image: (Artist’s impression): ESA/ATG medialab, CC BY-SA 3.0 IGO

ESA – 20 March 2018 The nature of planets orbiting stars in other systems will be the focus for ESA’s fourth medium-class science mission, to be launched in mid 2028.

Ariel, the Atmospheric Remote‐sensing Infrared Exoplanet Large‐survey mission, was selected by ESA today as part of its Cosmic Vision plan.

The mission addresses one of the key themes of Cosmic Vision: What are the conditions for planet formation and the emergence of life?

Thousands of exoplanets have already been discovered with a huge range of masses, sizes and orbits, but there is no apparent pattern linking these characteristics to the nature of the parent star. In particular, there is a gap in our knowledge of how the planet’s chemistry is linked to the environment where it formed, or whether the type of host star drives the physics and chemistry of the planet’s evolution.

Ariel will address fundamental questions on what exoplanets are made of and how planetary systems form and evolve by investigating the atmospheres of hundreds of planets orbiting different types of stars, enabling the diversity of properties of both individual planets as well as within populations to be assessed.

Observations of these worlds will give insights into the early stages of planetary and atmospheric formation, and their subsequent evolution, in turn contributing to put our own Solar System in context.

“Ariel is a logical next step in exoplanet science, allowing us to progress on key science questions regarding their formation and evolution, while also helping us to understand Earth’s place in the Universe,” says Günther Hasinger, ESA Director of Science.

“Ariel will allow European scientists to maintain competitiveness in this dynamic field. It will build on the experiences and knowledge gained from previous exoplanet mission
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The Kepler 90 System

The busy week of launches wasn’t the only thing going on of course, NASA announced the discovery of an eighth planet around a star called Kepler-90. The discovery was made using AI and the system is as large as our own.

Big news indeed.

From NASA: Our solar system now is tied for most number of planets around a single star, with the recent discovery of an eighth planet circling Kepler-90, a Sun-like star 2,545 light years from Earth. The planet was discovered in data from NASA’s Kepler Space Telescope. This artist’s concept depicts the Kepler-90 system compared with our own solar system.

The newly-discovered Kepler-90i — a sizzling hot, rocky planet that orbits its star once every 14.4 days — was found using machine learning from Google. Machine learning is an approach to artificial intelligence in which computers “learn.” In this case, computers learned to identify planets by finding in Kepler data instances where the telescope recorded changes in starlight caused by planets beyond our solar system, known as exoplanets.

NASA Ames manages the Kepler and K2 missions for NASA’s Science Mission Directorate. JPL managed Kepler mission development. Ball Aerospace & Technologies Corporation operates the flight system with support from the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder.

Image Credit: NASA/Ames Research Center/Wendy Stenzel

TRAPPIST-1

Using a collaboration of telescopes including TRAnsiting Planets and PlanetesImals Small Telescope–South,  seven new exo-planets have been found. Yesterday I eluded to all of them in the Goldilocks zone, that is not true but THREE of them are and ALL of the planets are relatively Earth-sized!

The star TRAPPIST-1 is a dwarf star,  TRAPPIST-1 is only estimated to be only eight percent (8%) of our Sun, so it’s really small.

You will notice these planets are collectively very close to their parent star and that means very fast orbital periods, ranging from just a-(Earth)day-and-a-half for the closest planet (b) to only about 20 days for the most distant planet (h).   Since the parent star is smaller and cooler that means the Goldilocks zone is much different than our own is.  Click the graphic above to be able to see the data.

 

Join The Search

If you have not participated in Zooniverse before, give it a try. I do a couple of the projects and will be doing this one too.

Backyard Worlds: Planet 9

Here is a description from Zooniverse I got in an email:
In this project you’ll be searching through images from NASA’s Wide-field Infrared Survey Explorer (WISE) mission, hunting for objects such as brown dwarfs and low-mass stars in our Solar System’s neighbourhood. You may find an object closer than Proxima Centauri (the closest star to the Sun) or even discover the Sun’s hypothesized ninth planet, which models suggest might appear in these images!

Verified 1284 New Planets

keplerupdate

Among the 1,284 newly found planets, nine of them are in the Goldilocks zone, where liquid water (and possibly life as we know it) could exist.  The count for these planets is now 21.

Here’s the press release:

NASA’s Kepler mission has verified 1,284 new planets – the single largest finding of planets to date.

“This announcement more than doubles the number of confirmed planets from Kepler,” said Ellen Stofan, chief scientist at NASA Headquarters in Washington. “This gives us hope that somewhere out there, around a star much like ours, we can eventually discover another Earth.”

Analysis was performed on the Kepler space telescope’s July 2015 planet candidate catalog, which identified 4,302 potential planets. For 1,284 of the candidates, the probability of being a planet is greater than 99 percent – the minimum required to earn the status of “planet.” An additional 1,327 candidates are more likely than not to be actual planets, but they do not meet the 99 percent threshold and will require additional study. The remaining 707 are more likely to be some other astrophysical phenomena. This analysis also validated 984 candidates previously verified by other techniques.

“Before the Kepler space telescope launched, we did not know whether exoplanets were rare or common in the galaxy. Thanks to Kepler and the research community, we now know there could be more planets than stars,” said Paul Hertz, Astrophysics Division director at NASA Headquarters. “This knowledge informs the future missions that are needed to take us ever-closer to finding out whether we are alone in the universe.”
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Mysterious Ripples Found

AU Microscopii
Source: Hubblesite.org

Hubblesite – Though astronomers have discovered thousands of planets orbiting other stars, very little is known about how they are born. The conventional wisdom is that planets coagulate inside a vast disk of gas and dust encircling newborn stars. But the details of the process are not well understood because it takes millions of years to happen as the disk undergoes numerous changes until it finally dissipates.

The young, nearby star AU Microscopii (AU Mic) is an ideal candidate to get a snapshot of planet birthing because the disk is tilted nearly edge on to our view from Earth. This very oblique perspective offers an opportunity to see structure in the disk that otherwise might go unnoticed. Astronomers are surprised to uncover fast-moving, wave-like features embedded in the disk that are unlike anything ever observed, or even predicted. Whatever they are, these ripples are moving at 22,000 miles per hour — fast enough to escape the star’s gravitational pull. This parade of blob-like features stretches farther from the star than Pluto is from our sun. They are so mysterious it’s not known if they are somehow associated with planet formation, or some unimagined, bizarre activity inside the disk.

Learn even more about AU Mic by joining the live Hubble Hangout discussion at 3:00 pm EDT on Thurs., Oct. 8 at http://hbbl.us/y6M.

SETI Talks About Kepler 452b

Here is a great video about the newly announced Kepler 452b with SETI scientists: Douglas Caldwell, Jeffrey Coughlin, Joseph Twicken. and hosted by Seth Shostak.

The Hangout fills in a lot of the blanks from the news reports.  As I expected we don’t yet have a mass or density on this planet. Once we get at least a good estimate on these numbers for 452b then we will be able to make better guesses on its composition.

We have an estimate of the diameter so that’s a start, but it’s only one bit of the equation that defines the balance the must exist. If for example, 452b has the density of Earth, we might expect an atmosphere to be much different than we have, ranging up to perhaps even Neptune-like. On the other hand the mass could be much less and the weaker gravity could allow more of the lighter gasses to be lost to space.

I am bound to guess we are very close to finding a real Earth analog. It is astounding how quickly the search is progressing.

Video