Exoplanets Archives

October 21, 2022October 21, 2022 by Carolyn Collins Petersen

Astronomers Find a “Marshmallow World”: the Lowest Density Gas Giant Ever Discovered

a gas giant orbiting a red dwarf star — A gas giant exoplanet [right] with the density of a marshmallow has been detected in orbit around a cool red dwarf star [left] by the NASA-funded NEID radial-velocity instrument on the 3.5-meter WIYN Telescope at Kitt Peak National Observatory, a Program of NSF’s NOIRLab. The planet, named TOI-3757 b, is the fluffiest gas giant planet ever discovered around this type of star.

Exoplanet discovery space hosts all kinds of interesting “super” worlds. There are super-Earths, super-Neptunes, and, of course, Super-Jupiters. Recently, the WIYN telescope on Kitt Peak in Arizona did a follow-up observation of a gas giant discovered by TESS (the Transiting Exoplanet Survey Satellite). The world is fluffy and weird and it’s orbiting a red giant star. Oddly enough, it shouldn’t even exist. Yet, there it is happily orbiting a star some 580 light-years from Earth.

October 21, 2022October 17, 2022 by Paul M. Sutter

Nitrous Oxide, aka “Laughing gas”, Could be an Indication of Life in an Exoplanet

Illustration showing the possible surface of TRAPPIST-1f, one of the newly discovered planets in the TRAPPIST-1 system. Credits: NASA/JPL-Caltech — Illustration showing the possible surface of TRAPPIST-1f, one of the newly discovered planets in the TRAPPIST-1 system. It's a very active flare star. Credits: NASA/JPL-Caltech

A team of astronomers have proposed to hunt for signs of life by looking for the signature of nitrous oxide in alien atmospheres. It’s laughing gas, but it’s no joke.

October 19, 2022October 19, 2022 by Evan Gough

The Heaviest Element Ever Seen in an Exoplanet’s Atmosphere: Barium

exoplanet hot jupiter transiting its star — This artist’s impression shows an ultra-hot exoplanet as it is about to transit in front of its host star. Credit: ESO

Astronomers have spotted barium in the atmosphere of a distant exoplanet. With its 56 protons, you have to run your finger further down the periodic table than astronomers usually do to find barium. What does finding such a heavy element in an exoplanet atmosphere mean?

It means we’re still learning how strange exoplanets can be.

October 18, 2022October 18, 2022 by Evan Gough

Scientists Discover a New Way Exoplanets Could Make Oxygen; Unfortunately, it Doesn’t Require Life

Oxygen is a valuable biosignature because Earth is oxygen-rich, and because life made all that oxygen. But if we find oxygen in an exoplanet atmosphere does that mean life made it? Or is there an abiotic source of oxygen? Image Credit: NASA

Finding oxygen in an exoplanet’s atmosphere is a clue that life may be at work. On Earth, photosynthetic organisms absorb carbon dioxide, sunlight, and water and produce sugars and starches for energy. Oxygen is the byproduct of that process, so if we can detect oxygen elsewhere, it’ll generate excitement. But researchers have also put pressure on the idea that oxygen in an exoplanet’s atmosphere indicates life. It’s only evidence of life if we can rule out other pathways that created the oxygen.

But scientists can’t rule them out.

October 14, 2022October 14, 2022 by Andy Tomaswick

If we Detect This gas on Other Planets, it’s a Good Sign There’s Life There

Here is an idea that likely never crossed the mind of most space enthusiasts – a gas emitted from broccoli (and other plants) is one of the most indicative signs of the existence of life on a planet. At least according to a new study from researchers at the University of California Riverside.

October 14, 2022October 16, 2022 by Evan Gough

If Earth Were an Exoplanet, it Would Still be Tricky to Figure Out if There’s Life Here

Earth as seen by the JUNO spacecraft in 2013. Credit: NASA/JPL-Caltech/SwRI/MSSS/Kevin M. Gill.

How would Earth appear to alien astronomers? What would their observations tell them about Earth if they searched the heavens for signs of habitability like we are? It’s a fun thought experiment.

But the experiment is more than just fun: it’s scientifically instructive. In many ways, it’s easier to study our planet and how it appears and then extrapolate those results as far as they go.

A new study shows that finding evidence of life on Earth may depend on the season alien astronomers are observing.

October 7, 2022October 7, 2022 by Brian Koberlein

A Solar Gravitational Lens Will be Humanity's Most Powerful Telescope. What are its Best Targets?

mage of a simulated Earth, at 1024×1024 pixel resolution, at the distance of Proxima Centauri,at 1.3 pc, as projectedby the SGL to an image plane at 650 AU from the Sun. Credit: Toth H. & Turyshev, S.G.

One of the central predictions of general relativity is that a massive object such as a star, galaxy, or black hole can deflect light passing nearby. This means that light from distant objects can be gravitationally lensed by objects closer to us. Under the right conditions, gravitational lensing can act as a kind of natural telescope, brightening and magnifying the light of distant objects. Astronomers have used this trick to observe some of the most distant galaxies in the universe. But astronomers have also thought about using this effect a little closer to home.

October 1, 2022October 1, 2022 by Andy Tomaswick

Earthlike Worlds With Oceans and Continents Could be Orbiting red Dwarfs, Detectable by James Webb

“Go then, there are other worlds than these.” Or so Stephen King said in his famous Dark Tower series. As of yet, none of those worlds are known to be like Earth. But, according to some new simulations by researchers at the National Astronomical Observatory of Japan (NAOJ), finding a genuinely Earth-like world might be in the cards by the decade’s end.

September 30, 2022September 30, 2022 by Carolyn Collins Petersen

Two “Super Mercury” Exoplanets Found in a Single System

Mercury gives a clue to Super-Mercuries — Astronomers have found a star system with two planets like Mercury, but bigger. Our own Mercury could supply clues to their composition and formation. (Credit: NASA/Johns Hopkins University/Applied Physics Laboratory.Carnegie Institution of Washington).

There’s a star system out there with three super-Earth planets and two super-Mercuries. Super-Earths are fairly familiar types of exoplanets, but super-Mercuries are rare. Those are planets with the same composition as our own Mercury, but larger and denser. Yet, here’s HD 23472, showing off two of eight known super-Mercuries in the galaxy.

September 21, 2022September 21, 2022 by Carolyn Collins Petersen

Habitable Planets Will Most Likely be Cold, Dry “Pale Yellow Dots”

An artist's concept of K2-18b, a super-Earth exoplanet that could support life. But, not all habitable planets are pale blue dots. Some are dry and yellow. Courtesy STScI

Remember all the habitable planets we’ve seen in science fiction movies? There’s wintry Hoth, for example, and overwhelmingly hot Dune. The folks in Interstellar visited an ocean world and a desolate rocky world. For all their differences, these places were still what they call on Star Trek M-class habitable worlds. Sure they weren’t all like Earth, but that made them excitingly alien for the lifeforms they did support. In the real universe, it seems that alien worlds not quite like ours could be the norm. Earth could be the real alien world.