Exoplanets Archives

December 11, 2023December 11, 2023 by Evan Gough

Exomoons Defy Discovery

So far we only know of two exoplanets with candidate exomoons. But even those two may be false positives. Image Credit: NASA

For a long time, we wondered if other stars hosted planets like the Sun does. Finally, in the 1990s, we got our answer. Now, another question lingers.

Most of the planets in our Solar System have moons. Do exoplanets have exomoons?

December 11, 2023December 11, 2023 by Nancy Atkinson

Amateur Astronomers Found Planets Crashing Into Each Other

Artist impression of two colliding planets.

Astronomy is one of the sciences where amateurs make regular contributions. Over the years, members of the public have made exciting discoveries and meaningful contributions to the scientific process, either through direct observing, citizen science projects, or through combing through open data from the various space missions.

Recently, amateur astronomer Arttu Sainio saw a conversation on X (Twitter) where researchers were discussing the strange behavior of a dimming sun-like star. Intrigued, Arttu decided to look at the data on this star, called Asassn-21qj, on his own. Looking at archival data from NASA’s NEOWISE mission, Sainio was surprised to find that the star had dimmed before, with an unexpected brightening in infrared light two years before the optical dimming event. So, he joined the discussion on social media and shared his finding – which led to more amateurs joining the research, which lead to an incredible discovery.

December 6, 2023December 6, 2023 by Evan Gough

ESA’s Ariel Mission is Approved to Begin Construction

An artist's impression of the ESA's Ariel space telescope. It'll examine 1,000 exoplanet atmospheres. Image Credit: ESA

We’re about to learn a lot more about exoplanets. The ESA has just approved the construction of its Ariel mission, which will give us our first large survey of exoplanet atmospheres. The space telescope will help us answer fundamental questions about how planets form and evolve.

December 6, 2023December 6, 2023 by Evan Gough

Astronomers Calculate Which Exoplanets Are Most Likely to Have Water

This illustration shows what the hot rocky exoplanet TRAPPIST-1 b could look like. A new method can help determine what rocky exoplanets might have large reservoirs of subsurface water. Credits: NASA, ESA, CSA, J. Olmsted (STScI)

Astronomers know of about 60 rocky exoplanets orbiting in the habitable zones of their stars. When they try to determine how habitable these planets might be, detecting water in their atmospheres plays a huge role. But what if there was another way of measuring the water content in these worlds?

Researchers are developing a way of modelling these worlds to determine how much water they have.

December 5, 2023December 5, 2023 by Evan Gough

This Planet is Way Too Big for its Star

This artist's illustration shows what the star LHS 3145 might look like from the surface of its planet, LHS 314b. Image Credit: Penn State / Penn State. Creative Commons

Scientists love outliers. Outliers are nature’s way of telling us what its boundaries are and where its limits lie. Rather than being upset when an outlier disrupts their understanding, scientists feed on the curiosity that outliers inspire.

It’s true in the case of a new discovery of a massive planet orbiting a small star. That goes against our understanding of how planets form, meaning our planet-formation model needs an update.

December 1, 2023December 1, 2023 by Beth Johnson

A Planetary System With Six Sub-Neptunes Locked in Perfect Resonance

SCIENCE & EXPLORATION Orbital geometry of HD110067 29/11/2023 457 VIEWS 19 LIKES 492309 ID LIKE DOWNLOAD XFacebookCopy LinkShare DETAILS RELATED Tracing a link between two neighbour planets at regular time intervals along their orbits, creates a pattern unique to each couple. The six planets of the HD110067 system together create a mesmerising geometric pattern due to their resonance-chain. — Credit: Thibaut Roger/NCCR PlanetS

A team of researchers led by University of Chicago astronomer Rafael Luque analyzed data acquired by both NASA’s Transiting Exoplanet Survey Satellite (TESS) and ESA’s CHaracterising ExOPlanet Satellite (Cheops) and found a unique planetary system. Orbiting a star cataloged as HD110067, this system contains six sub-Neptune planets. Incredibly, all six planets are orbiting in direct resonance with each other. The results of the work were published on November 29 in Nature.

November 25, 2023November 25, 2023 by Laurence Tognetti

Where are All the Double Planets?

Image comparing the sizes of Earth and its Moon (top right) and Pluto and its largest moon, Charon (bottom right). (Credit: NASA, JHUAPL, SWRI, Gregory H. Revera)

A recent study published in the Monthly Notices of the Royal Astronomical Society examines formation mechanisms for how binary planets—two large planetary bodies orbiting each other—can be produced from a type of tidal heating known as tidal dissipation, or the energy that is shared between two planetary bodies as the orbit close to each other, which the Earth and our Moon experiences. This study comes as the hunt for exomoons and other satellites orbiting exoplanets continues to expand and holds the potential to help astronomers better understand the formation and evolution of exoplanets and their systems. So, why is studying binary planets specifically important?

November 22, 2023November 22, 2023 by Evan Gough

Wow. JWST Just Found Methane in an Exoplanet Atmosphere

This artist’s rendering shows the warm exoplanet WASP-80 b. When viewed with human eyes, the colour may appear bluish due to the lack of high-altitude clouds and the presence of atmospheric methane identified by NASA’s James Webb Space Telescope. That makes it similar to the planets Uranus and Neptune in our own solar system. Image credit: NASA.

If there’s one chemical that causes excitement in the search for biosignatures on other worlds, it’s methane. It’s not a slam dunk because it has both biotic and abiotic sources. But finding it in an exoplanet’s atmosphere means that planet deserves a closer look.

November 16, 2023November 16, 2023 by Evan Gough

Hubble Succeeds Where TESS Couldn’t: It Measured the Nearest Transiting Earth-Sized Planet

This is an artist’s concept of the nearby exoplanet, LTT 1445Ac, which is a nearby Earth-size world. The planet orbits a red dwarf star. The star is in a triple system, with two closely orbiting red dwarfs seen at upper right. The black dot in front of the foreground star is planet LTT 1445Ab, transiting the face of the star. Image Credit: NASA, ESA, L. Hustak (STScI)

Twenty-two light-years away, a rocky world orbits a red dwarf. It’s called LTT 1445Ac, and NASA’s Transiting Exoplanet Survey Satellite (TESS) found it in 2022. However, TESS was unable to gauge the small planet’s size.

That’s okay. The venerable Hubble took care of it.

November 16, 2023November 16, 2023 by Evan Gough

Life Might Be Easiest to Find on Planets that Match an Earlier Earth

Artist's impression of the "pale orange dot" - what early Earth would have looked like. Credit: NASA/Goddard Space Flight Center/Francis Reddy

We’re inching closer and closer to reliably detecting biosignatures on distant planets. Much of the focus is on determining which chemicals indicate life’s presence.

But life can also create free energy in a system, and excess energy can create chemical disequilibrium. That’s what happened on Earth when life got going. Could chemical disequilibrium be a biosignature?