Exoplanets Archives

June 17, 2022June 17, 2022 by Nancy Atkinson

Using the Sun as a Gravitational Lens Would Let Us See Exoplanets With Incredible Resolution

An artist view of countless exoplanets. Credit: NASA/JPL-Caltech

Have you ever seen wispy arcs and rings in astronomical images taken by the Hubble Space Telescope and other observatories? These unusual features are caused by a quirk of nature called gravitational lensing, which occurs when light from a distant object is distorted by a closer massive object along the same line of sight. This distortion effectively creates a giant lens which magnifies the background light source, allowing astronomers to observe objects embedded within those lens-created arcs and rings that are otherwise be too far and too dim to see.

A group of researchers are working on plans to build a spacecraft that could apply this quirk by using our Sun as a gravitational lens. Their goal is to see distant exoplanets orbiting other stars, and to image an Earth-like exoplanet, seeing it in exquisite detail, at a resolution even better than the well-known Apollo 8 Earthrise photo.

June 16, 2022June 16, 2022 by Evan Gough

Two New Rocky Planets Discovered Close to the Solar System

An artist's illustration of two newly-discovered super-Earths. They're only 33 light years away and they orbit a red dwarf named HD 260655. Image Credit: NASA/JPL-Caltech

TESS has struck paydirt again. NASA’s planet-hunting spacecraft has found two new super-Earths orbiting a star only 33 light-years away. These are two of the closest rocky planets ever found.

June 15, 2022June 15, 2022 by Evan Gough

How Do Hot Jupiters Get So Close to Their Stars?

Thi illustration of a Hot Jupiter orbiting close to its star. Image Credit: ESA/ATG medialab, CC BY-SA 3.0 IGO

In this age of exoplanet discovery, we’ve discovered thousands of exoplanets of different types. The hot Jupiter is one of the most unusual types. There’s nothing like it in our Solar System.

Hot Jupiters are massive gas planets, and they attract a lot of attention because they’re so close to their stars and reach blistering temperatures. Their existence spawns a lot of questions about their formation and evolution. A new study is trying to answer some of those questions by determining hot Jupiters’ ages.

June 3, 2022June 3, 2022 by Andy Tomaswick

Objects That Share the Same Orbit are Common in the Solar System. But we’ve Never Seen co-Orbital Exoplanets. Why?

“Where are all the Trojans” is a question valid in both the study of ancient history and the study of exoplanets. Trojan bodies, which share orbital paths with other, larger planets, are prevalent in our solar system – most obviously in the Trojan asteroids that follow Jupiter around on its orbital path. However, they seem absent from any star system found with exoplanets. Now, a team of researchers from the SETI Institute and NASA’s Ames Research Center thinks they have found a reason why.

May 26, 2022May 26, 2022 by Evan Gough

“Wind-Ruffled Waves, Foam and Wave Shadows, Above Natural Blue Seawater.” This is how we’ll Spot Exoplanets With Oceans

Artist's depiction of a waterworld. A new study suggests that Earth is in a minority when it comes to planets, and that most habitable planets may be greater than 90% ocean. Credit: David A. Aguilar (CfA)

Our planet’s oceans generate tell-tale light signatures when sunlight reflects off them. Exoplanets with significant ocean coverage may do the same. Can we use the Earth’s reflectance signatures to identify other Earth-like worlds with large oceans?

We should be able to, eventually.

May 11, 2022May 11, 2022 by Evan Gough

These are the Best Places to Search for Habitable Exomoons

An artist's conception of a potentially-habitable exomoon. Credit: NASA

Our Solar System contains eight planets and more than 200 moons. The large majority of those moons have no chance of being habitable, but some of them—Europa and Enceladus, for example—are strong candidates in the search for life.

Is it the same in other solar systems?

May 5, 2022May 5, 2022 by Evan Gough

The Younger the Planet, the More Likely it is to be Habitable

This artist’s impression shows an example of a rogue planet with the Rho Ophiuchi cloud complex visible in the background. Rogue planets have masses comparable to those of the planets in our Solar System but do not orbit a star, instead roaming freely on their own. Image Credit: ESO/M. Kornmesser/S. Guisard

We’ve discovered thousands of exoplanets and are likely to find many thousands more of them. While the wide variety of planets we’ve found are scientifically interesting in their own right, what lurks behind all these discoveries is the search for a world that could harbour life.

But to sort the potentially habitable worlds from all the others, we need a way to filter through all of the exoplanets we keep discovering. We know that rocky worlds like Earth are the best places to look for habitable conditions, but according to a new study, age matters. We should pay special attention to young rocky worlds.

Why? Because youthful terrestrial planets have an internal heat source that’s critical for life.

April 27, 2022April 27, 2022 by Nancy Atkinson

Hubble has Characterized 25 Hot Jupiters. Here’s What we Know so far

Archival observations of 25 hot Jupiters by the NASA/ESA Hubble Space Telescope have been analysed by an international team of astronomers, enabling them to answer five open questions important to our understanding of exoplanet atmospheres. Amongst other findings, the team found that the presence of metal oxides and hydrides in the hottest exoplanet atmospheres was clearly correlated with the atmospheres' being thermally inverted.

Hot Jupiters are giant exoplanets – even more massive than Jupiter – but they orbit closer to their star than Mercury. When they were first discovered, hot Jupiters were considered oddballs, since we don’t have anything like them in our own Solar System. But they appear to be common in our galaxy. As exoplanets go, they are fairly easy to detect, but because we don’t have up-close experience with them, there are still many unknowns.

A new study used archival data from the Hubble and Spitzer space telescopes to study this class of giant gas exoplanets, and undertook one of the largest surveys ever of exoplanet atmospheres. The researchers said they employed high performance computers to analyses the atmospheres of 25 hot Jupiters using data from about 1,000 hours of telescope observations. Their findings, published in the Astrophysical Journal Supplement Series, help to answer several long-standing questions about hot Jupiters.

April 21, 2022April 21, 2022 by Brian Koberlein

Venus' Atmosphere Stops it From Locking to the Sun

Of the thousands of exoplanets we’ve discovered, most of them closely orbit red dwarf stars. Part of this is because planets with short orbital periods are easier to find, but part of this is that red dwarf stars make up about 75% of the stars in our galaxy. This propensity of close orbiting planets has some pretty big implications for “potentially habitable” worlds, not the least of which is that most of these planets are likely tidally locked to their star. Or so we’ve thought.

April 14, 2022April 14, 2022 by Evan Gough

A Fleet of Space Telescopes Flying in Formation Could Reveal Details on Exoplanets

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

We’ve found thousands of exoplanets in the last couple of decades. We’ve discovered exoplanets unlike anything in our own Solar System. But even with all we’ve found, it seems like there’s more and more to discover. Space scientists of all types are always working on the next generation of missions, which is certainly true for exoplanets.

Chinese researchers are developing an idea for an exoplanet-detecting array of space telescopes that acts as an interferometer. But it won’t only detect them. The array will use direct imaging to characterize distant exoplanets in more detail.