Subscribe free to our newsletters via your
. 24/7 Space News .




Subscribe free to our newsletters via your




















EXO WORLDS
First atmospheric study of Earth-sized exoplanets reveals rocky worlds
by Staff Writers
Boston MA (SPX) Jul 21, 2016


illustration only

On May 2, scientists from MIT, the University of Liege, and elsewhere announced they had discovered a planetary system, a mere 40 light years from Earth, that hosts three potentially habitable, Earth-sized worlds. Judging from the size and temperature of the planets, the researchers determined that regions of each planet may be suitable for life.

Now, in a paper published in Nature, that same group reports that the two innermost planets in the system are primarily rocky, unlike gas giants such as Jupiter. The findings further strengthen the case that these planets may indeed be habitable. The researchers also determined that the atmospheres of both planets are likely not large and diffuse, like that of the Jupiter, but instead compact, similar to the atmospheres of Earth, Venus, and Mars.

The scientists, led by first author Julien de Wit, a postdoc in MIT's Department of Earth, Atmospheric and Planetary Sciences, came to their conclusion after making a preliminary screening of the planets' atmospheres, just days after announcing the discovery of the planetary system.

On May 4, the team commandeered NASA's Hubble Space Telescope and pointed it at the system's star, TRAPPIST-1, to catch a rare event: a double transit, the moment when two planets almost simultaneously pass in front of their star. The researchers realized the planets would transit just two weeks before the event, thanks to refined estimates of the planets' orbital configuration, made by NASA's Spitzer Space Telescope, which had already started to observe the TRAPPIST-1 system.

"We thought, maybe we could see if people at Hubble would give us time to do this observation, so we wrote the proposal in less than 24 hours, sent it out, and it was reviewed immediately," de Wit recalls. "Now for the first time we have spectroscopic observations of a double transit, which allows us to get insight on the atmosphere of both planets at the same time."

Using Hubble, the team recorded a combined transmission spectrum of TRAPPIST-1b and c, meaning that as first one planet then the other crossed in front of the star, they were able to measure the changes in wavelength as the amount of starlight dipped with each transit.

"The data turned out to be pristine, absolutely perfect, and the observations were the best that we could have expected," de Wit says. "The force was certainly with us."

A rocky sign
The dips in starlight were observed over a narrow range of wavelengths that turned out not to vary much over that range. If the dips had varied significantly, de Wit says, such a signal would have demonstrated the planets have light, large, and puffy atmospheres, similar to that of the gas giant Jupiter.

But that's not the case. Instead, the data suggest that both transiting planets have more compact atmospheres, similar to those of rocky planets such as Earth, Venus, and Mars.

"Now we can say that these planets are rocky. Now the question is, what kind of atmosphere do they have?" de Wit says. "The plausible scenarios include something like Venus, where the atmosphere is dominated by carbon dioxide, or an Earth-like atmosphere with heavy clouds, or even something like Mars with a depleted atmosphere. The next step is to try to disentangle all these possible scenarios that exist for these terrestrial planets."

More eyes on the sky
The scientists are now working to establish more telescopes on the ground to probe this planetary system further, as well as to discover other similar systems. The planetary system's star, TRAPPIST-1, is known as an ultracool dwarf star, a type of star that is typically much cooler than the sun, emitting radiation in the infrared rather than the visible spectrum.

De Wit's colleagues from the University of Liege came up with the idea to look for planets around such stars, as they are much fainter than typical stars and their starlight would not overpower the signal from planets themselves.

The researchers discovered the TRAPPIST-1 planetary system using TRAPPIST (TRAnsiting Planets and PlanetesImals Small Telescope), a new kind of ground telescope designed to survey the sky in infrared.

TRAPPIST was built as a 60-centimeter prototype to monitor the 70 brightest dwarf stars in the southern sky. Now, the researchers have formed a consortium, called SPECULOOS (Search for habitable Planets Eclipsing ULtra-cOOl Stars), and are building four larger versions of the telescope in Chile, to focus on the brightest ultracool dwarf stars in the skies over the southern hemisphere. The researchers are also trying to raise money to build telescopes in the northern sky.

"Each telescope is about $400,000 - about the price of an apartment in Cambridge," de Wit says.

If the scientists can train more TRAPPIST-like telescopes on the skies, de Wit says, the telescopes may serve as relatively affordable "prescreening tools." That is, scientists may use them to identify candidate planets that just might be habitable, then follow up with more detailed observations using powerful telescopes such as Hubble and NASA's James Webb Telescope, which is scheduled to launch in October 2018.

"With more observations using Hubble, and further down the road with James Webb, we can know not only what kind of atmosphere planets like TRAPPIST-1 have, but also what is within these atmospheres," de Wit says. "And that's very exciting."

Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only

.


Related Links
Massachusetts Institute of Technology
Lands Beyond Beyond - extra solar planets - news and science
Life Beyond Earth






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

Previous Report
EXO WORLDS
NASA's Kepler Confirms 100+ Exoplanets During Its K2 Mission
Pasadena CA (JPL) Jul 19, 2016
An international team of astronomers has discovered and confirmed a treasure trove of new worlds using NASA's Kepler spacecraft on its K2 mission. Out of 197 initial planet candidates, scientists have confirmed 104 planets outside our solar system. Among the confirmed is a planetary system comprising four promising planets that could be rocky. These four planets, all between 20 and 50 perc ... read more


EXO WORLDS
SSTL and Goonhilly announce partnership and a call for lunar orbit payloads

Taiwan to make lunar lander for NASA moon-mining mission

NASA camera catches moon 'photobombing' Earth

Russia to spend $60M in 2016-2018 to fund space voyages to Moon, Mars

EXO WORLDS
NASA Selects Five Mars Orbiter Concept Studies

Next Mars Rover Progresses Toward 2020 Launch

Mars Canyons Study Adds Clues about Possible Water

Curiosity Mars Rover Enters Precautionary Safe Mode

EXO WORLDS
NASA Sails Full-Speed Ahead in Solar System Exploration

Disney theme park in Shanghai nears a million visitors

Sensor Technology Could Revolutionize What You Sleep On

Return to light for underground astronauts

EXO WORLDS
China's second space lab Tiangong-2 reaches launch center

Dutch Radio Antenna to Depart for Moon on Chinese Mission

Chinese Space Garbageman is not a Weapon

China to launch its largest carrier rocket later this year

EXO WORLDS
Russia launches ISS-bound cargo ship

New Crew Members, Including NASA Biologist, Launch to Space Station

Russian New Soyuz-MS Spacecraft Docks With ISS for First Time

NASA Highlights Space Station Research Benefits, Opportunities at San Diego Conference

EXO WORLDS
SpaceX propels cargo to space station, lands rocket

SpaceX to launch key 'parking spot' to space station

Russia to Continue Rocket Engine Supplies to US Under Existing Contracts

India launches 20 satellites in single mission

EXO WORLDS
Behind the scenes of protostellar disk formation

Surface Composition Determines Planet's Temperature and Habitability

Gemini Observatory Instrumental in Latest Exoplanet Harvest

Warm Jupiters Not as Lonely as Expected

EXO WORLDS
Fallout Fungi From Chernobyl Flee Earth on ISS Radiation Study Mission

Scientists move 1 step closer to creating an invisibility cloak

Setting a satellite to catch a satellite

New record in microwave detection




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News






The content herein, unless otherwise known to be public domain, are Copyright 1995-2017 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement