Patience Pays Off: Student Discovers Planets

Michelle Kunimoto, a student at the University of British Columbia, recently discovered four new exoplanets about 3,200 light years away - one close to Mercury in size, two somewhat larger that the Earth, and a fourth closer in size to Neptune.  Ms. Kunimoto is a recent graduate from UBC where she obtained a Bachelor’s degree in physics and astronomy.

How did she do it?  A part of her research as a student, Ms. Kunimoto was studying data from the Kepler Space Telescope, which contained observations of about 150,000 stars. She noticed something odd with one of the stars but it has been missed because of the exoplanets long orbit - 637 days. While Kepler has found other exoplanets with longer orbits, it appears more planets such as these could be in the data for discovery.

In fact, it was this time last year that a high school student in England was credited with finding a Jupiter-sized exoplanet 1,000 light years away. He was looking at data collected by the Wide Angle Search for Planets (WASP) project at Keele University in England, which uses an approach similar to the Kepler Space Telescope.

So the data is out there. Now we simply need more industrious (and patient) students to sort through it. 

Image: UBC student Michelle Kunimoto (right) and astronomy professor Jaymie Matthews (left). Martin Dee/UBC

Exoplanets: The Count Increases

NASA announced this week that scientists analyzing 2015 data from the refurbished Kepler space telescope, now called K2, has discovered another 1,284 exoplanets. This doubles the number of planets discover by the telescope since it was put into operation.

Among these newly discovered exoplanets, 550 are rocky like Earth and 9 are within their sun's habitable zone. As a result, the Kepler mission has discovered a total of 21 exoplanets that appear to be similar to Earth.

This is goods news as K2 continues its mission while other space telescope missions are being planned to help with the search in the near future.

Is Mars a Backup Planet?

With all the excitement about a someday trip to Mars, some are voicing caution that we should not be so eager to leave Earth behind.  Astronomer Lucianne Walkowicz from Chicago's Adler Planetarium in Chicago, who worked on NASA's Kepler mission, covered this idea in a recent TED talk titled Let's Not Use Mars as a Backup Planet.  In her March 2015 talk, posted in December, she noted we need to appreciate our home planet more than we do. 

Here is a quick summary of her talk:

Stellar astronomer and TED Senior Fellow Lucianne Walkowicz works on NASA's Kepler mission, searching for places in the universe that could support life. So it's worth a listen when she asks us to think carefully about Mars. In this short talk, she suggests that we stop dreaming of Mars as a place that we'll eventually move to when we've messed up Earth, and to start thinking of planetary exploration and preservation of the Earth as two sides of the same goal. As she says, "The more you look for planets like Earth, the more you appreciate our own planet."

You can get the transcript here.   

You can also learn more about Dr. Walkowicz and see her other talks here.

Kepler is Back!

It's great to see NASA has put the Kepler spacecraft back in action after a hiatus and some retooling.  Under its  second phase, called the K2 mission, Kepler has already detected a new exoplanet.  According to NASA, the planet was discovered during a test run of the K2 mission earlier this year: 

The newly confirmed planet, HIP 116454b, is 2.5 times the diameter of Earth and follows a close, nine-day orbit around a star that is smaller and cooler than our sun, making the planet too hot for life as we know it. HIP 116454b and its star are 180 light-years from Earth, toward the constellation Pisces.

While this may not be a livable planet for our purposes, it shows Kepler is back at work and helping us to expand our knowledge of other planetary systems.  With the costs of new spacecraft and related missions running ever higher, it is nice to know that recycling existing spacecraft can help us to do great science in the meantime.  

Kepler-186f: Finding the Needle in a Haystack of Data

The recent announcement that Kepler located an Earth-like planet 500 light years away was the product of detailed research on a trove of data collected during Kepler's lifetime.  Kepler-186f is similar to the size of Earth and within its star's habitable zone. The planet's sun is a dwarf star located in the constellation Cygnus.  The star is smaller than our sun and provides only about 1/3 the heat of our sun. A year on Kepler-186f, which is about 1.1 times the radius of the Earth, is about 130 days.

The full story can be found in Science magazine in a report titled "An Earth-Sized Planet in the Habitable Zone of a Cool Star."  Pretty straight forward like those all blue paintings titled "Blue."  The report abstract is a little more detailed:

The quest for Earth-like planets is a major focus of current exoplanet research. Although planets that are Earth-sized and smaller have been detected, these planets reside in orbits that are too close to their host star to allow liquid water on their surfaces. We present the detection of Kepler-186f, a 1.11 ± 0.14 Earth-radius planet that is the outermost of five planets, all roughly Earth-sized, that transit a 0.47 ± 0.05 solar-radius star. The intensity and spectrum of the star’s radiation place Kepler-186f in the stellar habitable zone, implying that if Kepler-186f has an Earth-like atmosphere and water at its surface, then some of this water is likely to be in liquid form.

It is possible that more such exoplanets may emerge from Kepler's archived data as scientists sift through the information.  While Kepler's original mission may have ended last year, the scientific community has plenty of data to play with for years to come.  It reminds me of archaeology, where digging can be the easy part while cataloging the find an putting together the various pieces takes many more years as association with other artifacts takes place and theories are confirmed.  

In a press release, NASA noted that we are not necessarily looking at a twin Earth but more likely a distant cousin:

 "Being in the habitable zone does not mean we know this planet is habitable. The temperature on the planet is strongly dependent on what kind of atmosphere the planet has," said Thomas Barclay, research scientist at the Bay Area Environmental Research Institute at Ames, and co-author of the paper. "Kepler-186f can be thought of as an Earth-cousin rather than an Earth-twin. It has many properties that resemble Earth."

Of course Kepler-186f is not the most interesting name.  Late night host Craig Ferguson had his own ideas recently, noting "I think we have to be more creative...This planet is big and old and surrounded by stars a fraction of its age.  Why don't we call it George Clooney."  Okay, maybe Mr. Ferguson can work on his astronomy and we can keep trying on the name.

Image Credit:  NASA Ames/SETI Institute/JPL-CalTech

More Earth-Like Planets Located

If you are looking for a little bit of bedtime reading, you could do worse than this 138 page paper from NASA titled "Validation of Kepler’s Multiple Planet Candidates. III: Light Curve Analysis & Announcement of Hundreds of New Multi-planet Systems."  Released on February 25th, the paper highlights the expoplanets found to date as well as a few new ones:

The Kepler mission has discovered over 2500 exoplanet candidates in the first two years of spacecraft data, with approximately 40% of them in candidate multi-planet systems. The high rate of multiplicity combined with the low rate of identified false-positives indicates that the multiplanet systems contain very few false-positive signals due to other systems not gravitationally bound to the target star (Lissauer, J. J., et al., 2012, ApJ 750, 131). False positives in the multi-planet systems are identified and removed, leaving behind a residual population of candidate multi-planet transiting systems expected to have a false-positive rate less than 1%. We present a sample of 340 planetary systems that contain 851 planets that are validated to substantially better than the 99% confidence level; the vast majority of these have not been previously verified as planets.

Among these 851 planets, the ones of particular interest are the "...768 planets across 306 systems being newly validated."  That is a nice collection of new new planets. 

For some reason, in its press release, NASA's Jet Propulsion Laboratory announced 715 new planets around 305 star systems. But why quibble?  But here is the important part:

Four of these new planets are less than 2.5 times the size of Earth and orbit in their sun's habitable zone, defined as the range of distance from a star where the surface temperature of an orbiting planet may be suitable for life-giving liquid water.  One of these new habitable zone planets, called Kepler-296f, orbits a star half the size and 5 percent as bright as our sun. Kepler-296f is twice the size of Earth, but scientists do not know whether the planet is a gaseous world, with a thick hydrogen-helium envelope, or it is a water world surrounded by a deep ocean.

I expect that more research on all the data acquired in the earlier Kepler mission will continue to bring forward new findings.  And, as noted earlier, Kepler may still have some life left for new missions.  

Image Credit:  NASA/JPL-Caltech/R. Hurt (SSC-Caltech)

More on Kepler from the 2013 Kepler Science Conference II

After discussing Kepler in my recent post, I wanted to learn more about the status of the Kepler mission.  You can find numerous papers from the November 2013 Kepler Science Conference II held at the NASA Ames Research Center at Moffett Field, California.  At this link you can view the agenda and get further links to papers and videos. 

One topic that was covered was the future of the Kepler spacecraft, launched in 2009.  While its primary mission may be over (though much data analysis remains), NASA believes it can still do some science with the damaged craft.  One of the slides from the Kepler Deputy Project Manger Charlie Sobek's presentation is shown below. 

The issue is finding a way to stabilize the orbit of the Kepler spacecraft with its two remaining wheels while also staying away from the "annoying" shine of the sun.  This next phase is called "K2."  The theory is that NASA can stabilize the spacecraft 4 days at a time before firing the thrusters so it continue with its science.  Luckily, most of this can still be done within budget since new funds are tight. 

NASA has been very creative in its efforts to salvage past missions, so hopefully Kepler can still do some great work in the years to come.

Top Astronomy Stories in 2013

This is the time of year to highlight some of the great discoveries of the last year, and we have plenty to ponder.  CBS news highlights events such as the discovery of the Higgs Boson, life in Antarctic lakes, more evidence of water on Mars, and the Chinese moon landing.  I would add the Indian mission to Mars as another key event.

CNN’s list of 2013 scientific stories included the stray asteroid that hit the Russian city of Chelyabinsk in February 2013 (notice this is a story rather than a discovery, though the people in Russia certainly discovered something new about the risk of life here on the third rock from the sun).

Wired magazine covered both discoveries and stories, with discoveries including estimates that our galaxy may contain about 10 billion Earth-like planets (using data from NASA’s Kepler space telescope).  Top stories included Mars One, the plan to send humans one-way to Mars in 10 years, and the mysterious environment encountered by Voyager 1 at the edge of the Sun’s heliosheath.  Wired also discusses the diminishing availability plutonium-238, which may impact out ability to repeat Voyager-like missions in the future.