It Took 10 Years to Confirm the First Planet Ever Found by Kepler

An illustration of the Kepler 1658 and Kepler 1658 b. Image Credit: Gabriel Perez Diaz/Instituto de Astrofísica de Canarias

Even though astronomy people are fond of touting the number of exoplanets found by the Kepler spacecraft, those planets aren’t actually confirmed. They’re more correctly called candidate exoplanets, because the signals that show something’s out there, orbiting a distant star, can be caused by something other than exoplanets. It can actually take a long time to confirm their existence.

Continue reading “It Took 10 Years to Confirm the First Planet Ever Found by Kepler”

This is Kepler’s Final Image

On October 30th, 2018, after nine years of faithful service, the Kepler Space Telescope was officially retired. With nearly 4000 candidates and 2,662 confirmed exoplanets to its credit, no other telescope has managed to teach us more about the worlds that exist beyond our Solar System. In the coming years, multiple next-generation telescopes will be deployed that will attempt to build on the foundation Kepler built.

And yet, even in retirement, Kepler is still providing us with impressive discoveries. For starters, NASA started the new year by announcing the discovery of several new exoplanets, including a Super-Earth and a Saturn-sized gas giant, as well as an unusually-sized planet that straddles these two categories. On top of that, NASA recently released the “last lighty” image and recordings obtained by Kepler before it ran out of fuel and ended its mission.

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Weekly Space Hangout – June 16, 2017: Dr. Natalie Batalha and NASA’s NExSS

Host: Fraser Cain (@fcain)

Special Guest:
Dr. Natalie Batalha is an astrophysicist at NASA Ames Research Center and project scientist for NASA’s Kepler Mission. Dr. Batalha leads the effort to understand planet populations in the galaxy based on Kepler’s discoveries, and in 2015 she joined the leadership team of NASA’s Nexus for Exoplanet System Science Coalition (NExSS,) a multidisciplinary team dedicated to searching for evidence of life beyond the Solar System as well as understanding the diversity of exoplanetary worlds and which of these worlds are most likely to harbor life.

On Monday, June 19, there will be a media event for ExoPlanet Week and NExSS, Kepler and K2! You can watch live-stream of briefing here. For a calendar of public ExoPlanet events in the Bay Area next week, check here.

Guests:
Paul M. Sutter (pmsutter.com / @PaulMattSutter)

Their stories this week:
Weighing a White Dwarf
Hottest Planet Ever
Spotting a Hidden Black Hole
Do we live in a void?

We use a tool called Trello to submit and vote on stories we would like to see covered each week, and then Fraser will be selecting the stories from there. Here is the link to the Trello WSH page (http://bit.ly/WSHVote), which you can see without logging in. If you’d like to vote, just create a login and help us decide what to cover!

Announcements:

The WSH recently welcomed back Mathew Anderson, author of “Our Cosmic Story,” to the show to discuss his recent update. He was kind enough to offer our viewers free electronic copies of his complete book as well as his standalone update. Complete information about how to get your copies will be available on the WSH webpage – just visit http://www.wsh-crew.net/cosmicstory for all the details.

If you would like to join the Weekly Space Hangout Crew, visit their site here and sign up. They’re a great team who can help you join our online discussions!

We record the Weekly Space Hangout every Friday at 12:00 pm Pacific / 3:00 pm Eastern. You can watch us live on Universe Today, or the Universe Today YouTube page

Weekly Space Hangout – April 28, 2017: Tim Blais of A Capella Science

Host: Fraser Cain (@fcain)

Special Guest:
Tim Blais is the founder of A Capella Science, an “educational and utterly nerdy online video project.” You can find his videos online on YouTube at A Capella Science.

Guests:
Jolene Creighton (fromquarkstoquasars.com / @futurism)

Their stories this week:
Total Eclipse of the Sun to be commemorated on a Forever Stamp

Kepler Stares at Neptune (NASA Video)

New Horizons 2.0

Joint mission to Europa could seek life under the ice

We use a tool called Trello to submit and vote on stories we would like to see covered each week, and then Fraser will be selecting the stories from there. Here is the link to the Trello WSH page (http://bit.ly/WSHVote), which you can see without logging in. If you’d like to vote, just create a login and help us decide what to cover!

Announcements:
On Friday, May 12, the WSH will welcome authors Michael Summers and James Trefil to the show to discuss their new book, Exoplanets: Diamond Worlds, Super Earths, Pulsar Planets and the New Search for Life Beyond Our Solar System. In anticipation of their appearance, the WSH Crew is pleased to offer our viewers a chance to win one of two hard cover copies of Exoplanets. Two winners will be drawn live by @fraser during our show on May 12th. To enter for a chance to win a copy of Exoplanets, send an email to: [email protected] with the Subject: Exoplanets. Be sure to include your name and email address in the body of your message so that we can contact the winners afterward. All entries must be electronically postmarked by 23:59 EST on May 10, 2017, in order to be eligible. No purchase necessary. Two winners will be selected at random from all eligible entries. Good luck!

If you’d like to join Fraser and Paul Matt Sutter on their Tour to Iceland in February 2018, you can find the information at astrotouring.com.

If you would like to join the Weekly Space Hangout Crew, visit their site here and sign up. They’re a great team who can help you join our online discussions!

We record the Weekly Space Hangout every Friday at 12:00 pm Pacific / 3:00 pm Eastern. You can watch us live on Universe Today, or the Universe Today YouTube page<

New System Discovered with Five Planets

A new study announced the discovery of a new system hosting five transiting planets (image credit: jhmart1/deviantart).
A new study announced the discovery of a system hosting five transiting planets (image credit: jhmart1/deviantart).

NASA’s planet-discovering Kepler mission suffered a major mechanical failure in May 2013, but thanks to innovative techniques subsequently implemented by astronomers the satellite continues to uncover worlds beyond our Solar System (i.e., exoplanets).  Indeed, Andrew Vanderburg (CfA) and colleagues just published results highlighting a new system found to host five transiting planets, which include: two sub-Neptune sized planets, a Neptune sized planet, a sub-Saturn sized planet, and a Jupiter sized planet.

Continue reading “New System Discovered with Five Planets”

What Are Planetary Transits?

Thanks to Ptolemy and his cronies, everyone used to think that the Earth was the center of the Solar System, with the Sun, planets and even the stars orbiting around it on a series of concentric crystal spheres. It was a clever idea, and explained the motions of the planets… sort of.

Then Copernicus figured out in 1543, that the Earth isn’t the centre of the Solar System. In fact, it’s just one planet in a vast Solar System, with objects whirling and whirling around the Sun.

With the structure of the Solar System figured out, and the crystal sphere idea in the garbage, astronomers still had a big unknown: how big is the Solar System?

Was it a few million kilometers across, or hundreds of millions. How big is the Sun? How far away is Venus?

Astronomers needed some kind of cosmic yardstick to measure everything against. Figure out one piece of the puzzle, and then you could measure everything else in relation.

In 1627, Johannes Kepler figured out that the motion of Venus was predictable, and that Venus would pass in front of the Sun in 1631, probably in the afternoon.

A timelapse of Mercury transiting across the face of the Sun. Credit: NASA
A timelapse of Mercury transiting across the face of the Sun. Credit: NASA

This is known as a “transit” of Venus.

The first crude measurements of Venus’ motion across the Sun were made in 1639 by Jeremiah Horrocks and William Crabtree from two different spots in England. And with these two observations, they were able to calculate the geometry between the Earth, Venus and the Sun.

If you recall all those memories you’re repressing from your high school geometry, once you’ve got an angle and a side of a triangle, you can work out all the other parts of the triangle. Horrocks and Crabtree worked out the distance from the Earth to the Sun within about 2/3rd accuracy. Not bad, considering the fact that astronomers literally had no idea before this point.

Following on from this observation, astronomers returned to their telescopes with each transit of Venus, better refining their calculations, and eventually settling on the current distance of about 150 million kilometers.

The 1882 transit of Venus.
The 1882 transit of Venus.

From here on Earth, we can see a few objects pass in front of the Sun: Venus, Mercury and the Moon.

Venus transits are the most rare, happening two times every 108 years or so. Mercury transits happen more often, about a dozen times a century. And a transit of the Moon, also known as a solar eclipse, happens a few times a year, on average.

It’s all a matter of perspective. If you’re standing on the Moon, you might see the Earth pass in front of the Sun. We’d call that a lunar eclipse, while the lunatics would call it an Earth transit.

We can also see transits in other parts of the Solar System, like when moons pass in front of planets. For example, if you have a small telescope, you can see when Jupiter’s larger moons pass in front of the planet from our perspective.

One of the questions you might have, though, is why don’t these transits happen more often. Why don’t we see a Mercury or Venus transit every time they line up with us and the Sun.

This is because the planets aren’t exactly lined up at the same angle towards the Sun. All of the planets are inclined at an angle that takes them above or below the Sun at various points of their orbit.

For example, Venus’ orbit is inclined 3 degrees off the Sun’s equator, while the Earth is inclined 7 degrees. This means that most of the time that Venus and Earth are lined up, Venus is either above or below the Sun.

Are you an ageless vampire, or planning to live a long time in multiple robot bodies, then you’re in luck. In the year 69,163, there’ll be a double transit on the surface of Sun with both Mercury and Venus at the same time. Enjoy that while you contemplate the horror of your existence.

Once we become a true Solar System civilization, there will be even more opportunities for transits. People living on Mars will be able to see Mercury, Venus and even transits of Earth passing in front of the Sun. Neptunians will be bored they can see them so often.

The transit method is one of the ways that astronomers discover planets orbiting other stars. Using a space telescope like Kepler, they survey a portion of the night sky, watching the brightness of thousands of stars. When a planet perfectly passes directly in between us and a star, Kepler detects a drop in brightness.

Since its deployment in 2007, Kepler has confirmed the existence of over 2000 extra-solar planets. Credit: NASA
Since its deployment in 2007, Kepler has confirmed the existence of over 2000 extra-solar planets. Credit: NASA

When you think of the geometries involved, it’s amazing this even happens at all. But the Universe is a vast place. Even if only a tiny percentage of star systems are perfectly lined up with us, there are enough to help us discover thousands and thousands of planets.

Kepler has turned up Earth-sized worlds orbiting other stars, some of which are even orbiting in their planet’s habitable zone.

Watching planetary transits is more than just a fun astronomy event, they’re how astronomers figured out the size of the Solar System itself. And now they help us find other planets orbiting other stars.

So, let’s agree to meet up in 2117 to catch the next transit of Venus, and celebrate this amazing event.

Weekly Space Hangout – May 13, 2016: Christer Fuglesang

Host: Fraser Cain (@fcain)

Special Guest:
Arne Christer Fuglesang is a Swedish physicist and an ESA astronaut. He was first launched aboard the STS-116 Space Shuttle mission on December 10, 2006, making him the first Swedish citizen in space.

Guests:
Morgan Rehnberg (MorganRehnberg.com / @MorganRehnberg)
Kimberly Cartier (@AstroKimCartier )

Their stories this week:

Kepler’s planet count doubles

An update on Boyajian’s Star

Boeing crewed launch slips to 2018

A four-planet system demonstrates migration

We’ve had an abundance of news stories for the past few months, and not enough time to get to them all. So we’ve started a new system. Instead of adding all of the stories to the spreadsheet each week, we are now using a tool called Trello to submit and vote on stories we would like to see covered each week, and then Fraser will be selecting the stories from there. Here is the link to the Trello WSH page (http://bit.ly/WSHVote), which you can see without logging in. If you’d like to vote, just create a login and help us decide what to cover!

We record the Weekly Space Hangout every Friday at 12:00 pm Pacific / 3:00 pm Eastern. You can watch us live on Google+, Universe Today, or the Universe Today YouTube page.

You can also join in the discussion between episodes over at our Weekly Space Hangout Crew group in G+!

Bayesian Analysis Rains On Exoplanet Life Parade

An exoplanet seen from its moon (artist's impression). Via the IAU.

Is there life on other planets, somewhere in this enormous Universe? That’s probably the most compelling question we can ask. A lot of space science and space missions are pointed directly at that question.

The Kepler mission is designed to find exoplanets, which are planets orbiting other stars. More specifically, its aim is to find planets situated in the habitable zone around their star. And it’s done so. The Kepler mission has found 297 confirmed and candidate planets that are likely in the habitable zone of their star, and it’s only looked at a tiny patch of the sky.

But we don’t know if any of them harbour life, or if Mars ever did, or if anywhere ever did. We just don’t know. But since the question of life elsewhere in the Universe is so compelling, it’s driven people with intellectual curiosity to try and compute the likelihood of life on other planets.

One of the main ways people have tried to understand if life is prevalent in the Universe is through the Drake Equation, named after Dr. Frank Drake. He tried to come up with a way to compute the probability of the existence of other civilizations. The Drake Equation is a mainstay of the conversation around the existence of life in the Universe.

The Drake Equation is a way to calculate the probability of extraterrestrial civilizations in the Milky Way that were technologically advanced to communicate. When it was created in 1961, Drake himself explained that it was really just a way of starting a conversation about extraterrestrial civilizations, rather than a definitive calculation. Still, the equation is the starting point for a lot of conversations.

But the problem with the Drake equation, and with all of our attempts to understand the likelihood of life starting on other planets, is that we only have the Earth to go by. It seems like life on Earth started pretty early, and has been around for a long time. With that in mind, people have looked out into the Universe, estimated the number of planets in habitable zones, and concluded that life must be present, and even plentiful, in the Universe.

But we really only know two things: First, life on Earth began a few hundred million years after the planet was formed, when it was sufficiently cool and when there was liquid water. The second thing that we know is that a few billions of years after life started, creatures appeared which were sufficiently intelligent enough to wonder about life.

In 2012, two scientists published a paper which reminded us of this fact. David Spiegel, from Princeton University, and Edwin Turner, from the University of Tokyo, conducted what’s called a Bayesian analysis on how our understanding of the early emergence of life on Earth affects our understanding of the existence of life elsewhere.

A Bayesian analysis is a complicated matter for non-specialists, but in this paper it’s used to separate out the influence of data, and the influence of our prior beliefs, when estimating the probability of life on other worlds. What the two researchers concluded is that our prior beliefs about the existence of life elsewhere have a large effect on any probabilistic conclusions we make about life elsewhere. As the authors say in the paper, “Life arose on Earth sometime in the first few hundred million years after the young planet had cooled to the point that it could support water-based organisms on its surface. The early emergence of life on Earth has been taken as evidence that the probability of abiogenesis is high, if starting from young-Earth-like conditions.”

A key part of all this is that life may have had a head start on Earth. Since then, it’s taken about 3.5 billion years for creatures to evolve to the point where they can think about such things. So this is where we find ourselves; looking out into the Universe and searching and wondering. But it’s possible that life may take a lot longer to get going on other worlds. We just don’t know, but many of the guesses have assumed that abiogenesis on Earth is standard for other planets.

What it all boils down to, is that we only have one data point, which is life on Earth. And from that point, we have extrapolated outward, concluding hopefully that life is plentiful, and we will eventually find it. We’re certainly getting better at finding locations that should be suitable for life to arise.

What’s maddening about it all is that we just don’t know. We keep looking and searching, and developing technology to find habitable planets and identify bio-markers for life, but until we actually find life elsewhere, we still only have one data point: Earth. But Earth might be exceptional.

As Spiegel and Turner say in the conclusion of their paper, ” In short, if we should find evidence of life that arose wholly idependently of us – either via astronomical searches that reveal life on another planet or via geological and biological studies that find evidence of life on Earth with a different origin from us – we would have considerably stronger grounds to conclude that life is probably common in our galaxy.”

With our growing understanding of Mars, and with missions like the James Webb Space Telescope, we may one day soon have one more data point with which we can refine our probabilistic understanding of other life in the Universe.

Or, there could be a sadder outcome. Maybe life on Earth will perish before we ever find another living microbe on any other world.

Weekly Space Hangout – Apr. 15, 2016: Dr. Howard Trottier

Host: Fraser Cain (@fcain)

Special Guest: Howard Trottier, a physics professor at Simon Fraser University (SFU) in British Columbia, Canada. Dr. Trottier has recently devoted his time to the development of SFU’s unique Astronomy public outreach program. In the heart of SFU’s main campus is a “”Science Courtyard,”” a high-profile public space devoted to astronomy and anchored by a state-of-the art outreach and teaching observatory. You can learn more about this amazing program here.

Guests:

Kimberly Cartier (@AstroKimCartier )
Dave Dickinson (www.astroguyz.com / @astroguyz)
Paul M. Sutter (pmsutter.com / @PaulMattSutter)

Their stories this week:

Breakthrough Starshot mission to Alpha Centauri program

Kepler spacecraft temporarily in emergency mode

Mercury Transit

Huge Sunspot

We’ve had an abundance of news stories for the past few months, and not enough time to get to them all. So we’ve started a new system. Instead of adding all of the stories to the spreadsheet each week, we are now using a tool called Trello to submit and vote on stories we would like to see covered each week, and then Fraser will be selecting the stories from there. Here is the link to the Trello WSH page (http://bit.ly/WSHVote), which you can see without logging in. If you’d like to vote, just create a login and help us decide what to cover!

We record the Weekly Space Hangout every Friday at 12:00 pm Pacific / 3:00 pm Eastern. You can watch us live on Google+, Universe Today, or the Universe Today YouTube page.

You can also join in the discussion between episodes over at our Weekly Space Hangout Crew group in G+!