Exoplanets Archives

February 16, 2023February 16, 2023 by Evan Gough

What Would Happen if the Solar System Gained a Super-Earth?

This illustration shows the super-Earth exoplanet 55 Cancri e with its star. What would our Solar System be like if it was home to a super-Earth like this one? Credit: NASA/JPL

In this era of exoplanet discovery, astronomers have found over 5,000 confirmed exoplanets, with thousands more awaiting confirmation and many billions more waiting to be discovered. These exoplanets exist in a bewildering spectrum of sizes, compositions, orbital periods, and just about every other characteristic that can be measured.

Learning about them has also shed light on our Solar System. We used to think of it as an archetypal arrangement of planets since it’s all we had to go on. But now we know we might be the outlier because we have no Super-Earth.

February 8, 2023February 9, 2023 by Laurence Tognetti

Astronomers still scratching their heads over population of ocean-world exoplanets

Artist rendition of a potential water-world exoplanet that might support advanced civilizations. Such life could advertise its existence via technosignatures from industrial or other activities. (Credit: ESA / Hubble / M. Kornmesser) — Artist rendition of a potential water-world exoplanet that might support life. Scientists could determine whether to explore this world based on its planetary entropy production. (Credit: ESA / Hubble / M. Kornmesser)

In a recent study submitted to The Astrophysical Journal Letters, an international team of researchers led by the University of California, Los Angeles (UCLA) examine the potential for water-worlds around M-dwarf stars. Water-worlds, also known as ocean worlds, are planets that possess bodies of liquid water either directly on its surface, such as Earth, or somewhere beneath it, such as Jupiter’s moon, Europa and Saturn’s moon, Enceladus.

February 6, 2023February 6, 2023 by Evan Gough

Earth-Sized Planet Found At One of the Lightest Red Dwarfs

Artist’s conception of a rocky Earth-mass exoplanet like Wolf 1069 b orbiting a red dwarf star. If the planet has retained its atmosphere, chances are high that it would feature liquid water and habitable conditions over a wide area of its dayside. Image Credit: NASA/Ames Research Center/Daniel Rutter

Astronomers have found another Earth-sized planet. It’s about 31 light-years away and orbits in the habitable zone of a red dwarf star. It’s probably tidally locked, which can be a problem around red dwarf stars. But the team that found it is optimistic about its potential habitability.

February 2, 2023February 2, 2023 by Evan Gough

How Can We Know if We’re Looking at Habitable exo-Earths or Hellish exo-Venuses?

How can astronomers tell exo-Earths and exo-Venuses apart? Polarimetry might be the key. Image Credits: NASA

The differences between Earth and Venus are obvious to us. One is radiant with life and adorned with glittering seas, and the other is a scorching, glowering hellhole, its volcanic surface shrouded by thick clouds and visible only with radar. But the difference wasn’t always clear. In fact, we used to call Venus Earth’s sister planet.

Can astronomers tell exo-Earths and exo-Venuses apart from a great distance?

January 31, 2023January 31, 2023 by Nancy Atkinson

Watch This 12-Year Timelapse of Exoplanets Orbiting Their Star

Four faint exoplanets orbit star HR8799, which is represented by a star-shaped icon in the center. (The star itself was removed from the video because its glare is so intense that it blocks out the surrounding planets.) Credit: Jason Wang/Northwestern University.

Back in 2008, astronomers made a big announcement: for the first time, they had taken pictures of a multi-planet solar system, much like ours, orbiting another star. At the time, the star system, named HR8799 was known to have three planets, but follow-up observations a year later revealed a fourth world.

Astronomers have continued to watch this intriguing star system, and now, using observations from the last 12 years, astrophysicist Jason Wang has put together a time lapse video showing the orbital motions of the four planets.

January 27, 2023January 27, 2023 by Evan Gough

It’s Already Hard Enough to Block a Single Star’s Light to See its Planets. But Binary Stars? Yikes

Binary stars are common and imaging their planets will be a challenge. How can astronomers block all that light so they can see the planets? This artist's illustration shows the eclipsing binary star Kepler 16, as seen from the surface of an exoplanet in the system. Image Credit: NASA

Detecting exoplanets was frontier science not long ago. But now we’ve found over 5,000 of them, and we expect to find them around almost every star. The next step is to characterize these planets more fully in hopes of finding ones that might support life. Directly imaging them will be part of that effort.

But to do that, astronomers need to block out the light from the planets’ stars. That’s challenging in binary star systems.

January 18, 2023January 18, 2023 by Evan Gough

Could Next-Generation Telescopes See That Earth Has Life?

In this image, Earthshine lights up the dark portion of the lunar surface. Image Credit: NASA

While the Earth absorbs a lot of energy from the Sun, a lot of it is reflected back into space. The sunlight reflected from Earth is called Earthshine. We can see it on the dark portion of the Moon during a crescent Moon. The Farmer’s Almanac said it used to be called “the new Moon in the old Moon’s arms.”

Earthshine is one instance of planetshine, and when we look at the light from distant exoplanets, we’re looking directly at their planetshine without it bouncing off another object.

If distant astronomers were looking at Earthshine the way we look at exoplanet shine, would the light tell them our planet is rippling with life?

January 18, 2023January 18, 2023 by Evan Gough

By Blocking the Light From a Star, Webb Reveals the Dusty Disk Surrounding It

These coronagraphic images of a disk around the star AU Microscopii, captured by Webb’s Near-Infrared Camera (NIRCam), show compass arrows, scale bar, and color key for reference. Image Credit: SCIENCE: NASA, ESA, CSA, Kellen Lawson (NASA-GSFC), Joshua E. Schlieder (NASA-GSFC) IMAGE PROCESSING: Alyssa Pagan (STScI)

AU Microscopii is a small red dwarf star about 32 light-years away. It’s far too dim for the unaided human eye, but that doesn’t diminish its appeal. The star has at least two exoplanets and hosts a circumstellar debris disk.

It’s also young, only about 23 million years old, and it’s the second-closest pre-main sequence star to Earth. The JWST recently imaged the star and its surroundings and found something surprising.

January 17, 2023January 17, 2023 by Evan Gough

Worlds Bustling With Plantlife Should Shine in a Detectable Wavelength of Infrared

Artist's rendering of a super-Earth-type exoplanet, TOI 1452 b. Credit: Benoit Gougeon, Université de Montréal.

Future historians might look back on this time and call it the ‘exoplanet age.’ We’ve found over 5,000 exoplanets, and we’ll keep finding more. Next, we’ll move beyond just finding them, and we’ll turn our efforts to finding biosignatures, the special chemical fingerprints that living processes imprint on exoplanet atmospheres.

But there’s more to biosignatures than atmospheric chemistry. On a planet with lots of plant life, light can be a biosignature, too.

January 13, 2023January 13, 2023 by Evan Gough

TESS has Found A Second Earth-Sized World in This System. Exoplanet Science is Maturing

Newly discovered Earth-size planet TOI 700 e orbits within the habitable zone of its star in this illustration. New research questions whether planets are necessary for life. Image Credit: NASA/JPL-Caltech/Robert Hurt

For planet-hunters, finding an Earth-sized exoplanet must be special. NASA estimates there are about 100 billion planets in the Milky Way, but the large majority of the 5,000+ exoplanets we’ve found are extremely inhospitable. So finding one that’s similar to ours is kind of comforting.

In this case, it’s even more interesting because it’s the second Earth-sized planet orbiting the same star.