exoplanets Archives

August 26, 2019August 26, 2019 by Matt Williams

There Could be Planets Out There Which are Even More Habitable than Earth

Artist’s impression of a Super-Earth planet orbiting a Sun-like star. Credit: ESO/M. Kornmesser

When searching for potentially habitable exoplanets, scientists are forced to take the low-hanging fruit approach. Since Earth is the only planet we know of that is capable of supporting life, this search basically comes down to looking for planets that are “Earth-like”. But what if Earth is not the meter stick for habitability that we all tend to think it is?

That was the subject of a keynote lecture that was recently made at the Goldschmidt Geochemistry Congress, which took place from Aug. 18th to 23rd, in Barcelona, Spain. Here, a team of NASA-supported researchers explained how an examination of what goes into defining habitable zones (HZs) shows that some exoplanets may have better conditions for life to thrive than Earth itself has.

August 21, 2019August 21, 2019 by Matt Williams

Earth is an Exoplanet to Aliens. This is What They’d See

Reconstruction of what Earth's light curve would look like. Credit: S. Fan et. al., arXiv (2019) arXiv:1908.04350

The study of exoplanets has matured considerably in the last ten years. During this time, the majority of the over 4000 exoplanets that are currently known to us were discovered. It was also during this time that the process has started to shift from the process of discovery to characterization. What’s more, next-generation instruments will allow for studies that will reveal a great deal about the surfaces and atmospheres of exoplanets.

This naturally raises the question: what would a sufficiently-advanced species see if they were studying our planet? Using multi-wavelength data of Earth, a team of Caltech scientists was able to construct a map of what Earth would look like to distant alien observers. Aside from addressing the itch of curiosity, this study could also help astronomers reconstruct the surface features of “Earth-like” exoplanets in the future.

August 9, 2019August 9, 2019 by Fraser Cain

One Year, Almost 1,000 Planetary Candidates. An Update On TESS

NASA’s Transiting Exoplanet Survey Telescope launched back in April, 2018. After a few months of testing, it was ready to begin mapping the southern sky, searching for planets orbiting stars relatively nearby.

We’re just over a year into the mission now, and on July 18th, TESS has shifted its attention to the Northern Hemisphere, continuing the hunt for planets in the northern skies.

August 3, 2019August 3, 2019 by Evan Gough

Snowball Exoplanets Might Be Better for Life Than We Thought

This artist's illustration shows what an icy exo-Earth might look like. A new study says liquid water could persist under ice sheets on planets outside of their habitable zones. Image Credit: NASA

When astronomers discover a new exoplanet, one of the first considerations is if the planet is in the habitable zone, or outside of it. That label largely depends on whether or not the temperature of the planet allows liquid water. But of course it’s not that simple. A new study suggests that frozen, icy worlds with completely frozen oceans could actually have livable land areas that remain habitable.

The new study was published in the AGU’s Journal of Geophysical Research: Planets. It focuses on how CO2 cycles through a planet and how it affects the planet’s temperature. The title is “Habitable Snowballs: Temperate Land Conditions, Liquid Water, and Implications for CO₂ Weathering.”

July 31, 2019July 31, 2019 by Evan Gough

NASA Promised More Smaller, Earth-size Exoplanets. TESS is Delivering.

This infographic illustrates key features of the TOI 270 system, located about 73 light-years away in the southern constellation Pictor. The three known planets were discovered by NASA’s Transiting Exoplanet Survey Satellite through periodic dips in starlight caused by each orbiting world. Insets show information about the planets, including their relative sizes, and how they compare to Earth. Temperatures given for TOI 270’s planets are equilibrium temperatures, calculated without the warming effects of any possible atmospheres. Credit: NASA’s Goddard Space Flight Center/Scott Wiessinger

When NASA launched TESS (Transiting Exoplanet Survey Satellite) in 2018, it had a specific goal. While its predecessor, the Kepler spacecraft, found thousands of exoplanets, many of them were massive gas giants. TESS was sent into space with a promise: to find smaller planets similar in size to Earth and Neptune, orbiting stable stars without much flaring. Those constraints, astronomers hoped, would identify more exoplanets that are potentially habitable.

With this discovery of three new exoplanets, TESS is fulfilling its promise.

July 15, 2019July 15, 2019 by Evan Gough

Here’s a First. Astronomers See a Moon Forming Around a Baby Exoplanet

A color-enhanced image of millimeter-wave radio signals from the ALMA observatory in Chile shows a disk of gas and dust (right of center) around exoplanet PDS 70 c, the first-ever observation of the kind of circumplanetary disk that is believed to have birthed the moons of Jupiter more than 4 billion years ago. CREDIT A. Isella, ALMA (ESO/NAOJ/NRAO))

Astronomers have discovered, for the first time, moons forming in the disk of debris around a large exoplanet. Astronomers have suspected for a long time that this is how larger planets—like Jupiter in our own Solar System—get their moons. It’s all happening around a very young star named PDS 70, about 370 light years away in the constellation Centaurus.

July 3, 2019July 3, 2019 by Matt Williams

The Planet-Hunting TESS Discovers Its Smallest Exoplanet to Date

The three planets discovered in the L98-59 system by NASA’s Transiting Exoplanet Survey Satellite (TESS) are compared to Mars and Earth in order of increasing size in this illustration. Credit: NASA’s Goddard Space Flight Center

Thanks in large part to the Kepler Space Telescope, the number of confirmed extrasolar planets has grown exponentially in the last decade. And with next-generation missions like the Transiting Exoplanet Survey Satellite (TESS) already in orbit, more candidates and confirmed planets are being discovered all the time – many of them new and exciting ones too!

In fact, one of TESS’ most recent discoveries includes a three-planet system that orbits a star (L 98-59) located roughly 35 light-years from Earth. One of the planets, known as L 98-59b, is between the sizes of Earth and Mars – effectively making it the smallest exoplanet discovered by TESS to date. The discovery also highlights the sophistication of TESS and doubles the number of small exoplanets that are considered worthy of follow-up studies.

June 19, 2019June 19, 2019 by Matt Williams

Two Earth-Like Worlds Found Orbiting a Red Dwarf Only 12.5 Light-Years Away

Artistic recreation of the Teegarden Star system. Credit: University of Göttingen

In the past few decades, there has been an explosion in the number of planets discovered beyond our Solar System. With over 4,000 confirmed exoplanets to date, the process has gradually shifted from discovery towards characterization. This consists of using refined techniques to determine just how likely a planet is to be habitable.

At the same time, astronomers continue to make discoveries regularly, some of which are right in our cosmic backyard. For instance, an international team of researchers recently detected two new Earth-like planets orbiting Teegarden’s Star, an M-type (red dwarf) star located just 12.5 light-years from the Solar System in the direction of the Aries constellation.

June 19, 2019June 19, 2019 by Evan Gough

Competition Will Let You Name an Exoplanet

Within the framework of its 100th anniversary commemorations, the International Astronomical Union (IAU) is organising the IAU100 NameExoWorlds global competition that allows any country in the world to give a popular name to a selected exoplanet and its host star. Image Credit: IAU/L. Calçada

When it comes to naming all those exoplanets that astronomers keep finding, it’s up to the International Astronomical Union (IAU) to do the job. In an effort to reach out to the global community, they’re running a new contest. In honour of their 100 year anniversary, the IAU has organized the 100IAU NameExoWorlds event.

June 13, 2019June 14, 2019 by Matt Williams

In Order to Reveal Planets Around Another star, a Starshade Needs to Fly 40,000 km Away from a Telescope, Aligned Within Only 1 Meter

Artist's concept of the prototype starshade, a giant structure designed to block the glare of stars so that future space telescopes can take pictures of planets. Credit: NASA/JPL

To assist with future efforts to locate and study exoplanets, engineers with NASA’s Jet Propulsion Laboratory – in conjunction with the Exoplanet Exploration Program (ExEP) – are working to create Starshade. Once deployed, this revolutionary spacecraft will help next-generation telescopes by blocking out the obscuring light coming from distant stars so exoplanets can be imaged directly.

While this may sound pretty straightforward, the Starshade will also need to engage in some serious formation flying in order to do its job effectively. That was the conclusion of the reached by the Starshade Technology Development team (aka. S5) Milestone 4 report – which is available through the ExEP website. As the report stated, Starshade will need to be perfectly aligned with space telescopes, even at extreme distances.