Astronomers Have Found the Perfect Exoplanet to Study Another World’s Atmosphere

An artist's rendering of TOI-1231 b, a Neptune-like planet about 90 light years away from Earth. Credit: NASA/JPL-Caltech

TESS (Transiting Exoplanet Survey Satellite) has found a new planet, and the discovery of this sub-Neptune exoplanet has scientists excited about atmospheres. The combination of the planet’s size, its thick atmosphere, and its orbit around a small M-class star close to Earth provides researchers with an opportunity to learn more about exoplanet atmospheres. We’re getting better and better at finding exoplanets, and studying their atmospheres is the next step in understanding them as a whole.

Continue reading “Astronomers Have Found the Perfect Exoplanet to Study Another World’s Atmosphere”

What’s the Connection Between the Chemistry of a Star and the Formation of its Planets?

Scientists seem to have come up with a new parlor game – how many ways can we potentially detect exoplanets?  The two most common methods, the transit method and the Doppler method, each have their own problems.  Alternative methods are starting to sprout up, and a new one was recently proposed by Jacob Nibauer, an undergraduate student in the University of Pennsylvania’s Department of Physics and Astronomy.  His suggestion: look at a star’s chemical composition. And his findings after analyzing data on some 1,500 stars hold some surprises.

Continue reading “What’s the Connection Between the Chemistry of a Star and the Formation of its Planets?”

How To Search the Chemical Makeup of Exoplanet Atmospheres for Hints at Their History

Author’s note – this article was written with Dr. Vincent Kofman, a scientist at NASA’s Goddard Space Flight Center (GSFC), working in the Sellers Exoplanet Environments Collaboration (SEEC), and the lead author on the research it discusses.

Thousands of exoplanets have been discovered in the recent decades. Planet hunters like TESS and Kepler, as well as numerous ground-based efforts, have pushed the field and we are starting to get a total number of planets that will allow us to perform effective statistical analysis on some of them.

Not only do the detected number of planets show us how common they are; it exposes our lack of understanding about how planets form, what conditions are present, and when planets may be habitable. The transit detection of an exoplanet primarily yields the orbital period, or the length of a year on the planet, and the relative size of the planet with respect to the star. The next steps are to characterize the planet. This usually requires follow up studies, using different observational strategies and more powerful telescopes.

Continue reading “How To Search the Chemical Makeup of Exoplanet Atmospheres for Hints at Their History”

The Moons of Rogue Planets Could Have Liquid Surface Water and Thick Atmospheres. They Could be Habitable

Artist's rendering of an Earth-sized rogue planet approaching a star. Credit: Christine Pulliam (CfA)

The search for life on exoplanets takes a fairly conservative approach. It focuses on life that is similar to that of Earth. Sure, it’s quite possible that life comes in many exotic forms, and scientists have speculated about all the strange forms life might take, but the simple fact is that Earth life is the only form we currently understand. So most research focuses on life forms that, like us, are carbon based with a biology that relies on liquid water. But even with that narrow view, life could still be hiding in places we don’t expect.

Continue reading “The Moons of Rogue Planets Could Have Liquid Surface Water and Thick Atmospheres. They Could be Habitable”

Exoplanet Surveys are Leaning Towards the Possibility That our Solar System is… Normal

One of the unspoken caveats of most exoplanet discovery missions is that they only operate for a few years.  Such a short observing window means there are planets with longer orbital periods, usually further out from the star, that those surveys would completely miss.  Knowing this would be a problem, a team of astronomers arranged the California Legacy Survey three decades ago in order to monitor as many stars as possible for as long a time as possible.  Recently they released their first results, which show solar systems that are surprisingly like our own.

Continue reading “Exoplanet Surveys are Leaning Towards the Possibility That our Solar System is… Normal”

Larger Rocky Planets Might be Rare Because They Shrunk

Researchers at the Flatiron Institute’s Center for Computational Astrophysics published a paper last week that just might explain a mysterious gap in planet sizes beyond our solar system. Planets between 1.5 and 2 times Earth’s radius are strikingly rare. This new research suggests that the reason might be because planets slightly larger than this, called mini-Neptunes, lose their atmospheres over time, shrinking to become ‘super-Earths’ only slightly larger than our home planet. These changing planets only briefly have a radius the right size to fill the gap, quickly shrinking beyond it. The implication for planetary science is exciting, as it affirms that planets are not static objects, but evolving and dynamic worlds.

Continue reading “Larger Rocky Planets Might be Rare Because They Shrunk”

Hydroxyl (OH) Seen for the First Time in an Exoplanet Atmosphere

Artist's concept of a hot Jupiter exoplanet orbiting a star similar to tau Boötes (Image used with permission of David Aguilar, Harvard-Smithsonian Center for Astrophysics)

The molecule hydroxyl (HO) is common on Earth, but astronomers have not yet determined how abundant it is on other worlds. For the first time, astronomers have conclusively detected it in the atmosphere of an ultra-hot Jupiter, WASP-33b.

Continue reading “Hydroxyl (OH) Seen for the First Time in an Exoplanet Atmosphere”

Astronomers are Watching a gas Giant Grow, Right in Front of Their Eyes

In the vastness of space, astronomers are likely to find instances of almost every astronomical phenomena if they look hard enough.  Many planetary phenomena are starting to come into sharper focus as the astronomy community continues to focus on finding exoplanets.  Now a team led by Yifan Zhou at UT Austin has directly imaged a gas giant still in formation.

Continue reading “Astronomers are Watching a gas Giant Grow, Right in Front of Their Eyes”

A Recent Megaflare Shows that Proxima Centauri is not a Nice Place to Live

An artist's conception of a violent flare erupting from the red dwarf star Proxima Centauri. Such flares can obliterate atmospheres of nearby planets. Credit: NRAO/S. Dagnello.
An artist's conception of a violent flare erupting from the red dwarf star Proxima Centauri. Such flares can obliterate atmospheres of nearby planets. Credit: NRAO/S. Dagnello.

Proxima b, the closest exoplanet to our Solar System, has been a focal point of scientific study since it was first confirmed (in 2016). This terrestrial planet (aka. rocky) orbits Proxima Centauri, an M-type (red dwarf) star located 4.2 light-years beyond our Solar System – and is a part of the Alpha Centauri system. In addition to its proximity and rocky composition, it is also located within its parent star’s habitable zone (HZ).

Until a mission can be sent to this planet (such as Breakthrough Starshot), astrobiologists are forced to postulate about the possibility that life could exist there. Unfortunately, an international campaign that monitored Proxima Centauri for months using nine space- and ground-based telescopes recently spotted an extreme flare coming from the star, one which would have rendered Proxima b uninhabitable.

Continue reading “A Recent Megaflare Shows that Proxima Centauri is not a Nice Place to Live”

Giant Planet is Found at an Extreme Distance From its Star

One of the best things about the sheer number of exoplanets that astronomers are currently finding is how some are just very different. Those differences can sometimes undermine standing theories, and prompt scientists to start considering new theories that account for the new information.  That is undoubtedly what will happen to accommodate a new massive planet found by a team led by Dutch scientists.  This planet is unique in one very special way – it is about 110 times farther away from its star than the Earth is from the sun.

Continue reading “Giant Planet is Found at an Extreme Distance From its Star”