. 24/7 Space News .
EXO WORLDS
TRAPPIST-1 Planets Probably Rich in Water
by Staff Writers
Garching, Germany (SPX) Feb 06, 2018

Artist's impressions of the TRAPPIST-1 planetary system

A new study has found that the seven planets orbiting the nearby ultra-cool dwarf star TRAPPIST-1 are all made mostly of rock, and some could potentially hold more water than Earth. The planets' densities, now known much more precisely than before, suggest that some of them could have up to 5 percent of their mass in the form of water - about 250 times more than Earth's oceans.

The hotter planets closest to their parent star are likely to have dense steamy atmospheres and the more distant ones probably have icy surfaces. In terms of size, density and the amount of radiation it receives from its star, the fourth planet out is the most similar to Earth. It seems to be the rockiest planet of the seven, and has the potential to host liquid water.

Planets around the faint red star TRAPPIST-1, just 40 light-years from Earth, were first detected by the TRAPPIST-South telescope at ESO's La Silla Observatory in 2016.

In the following year further observations from ground-based telescopes, including ESO's Very Large Telescope and NASA's Spitzer Space Telescope, revealed that there were no fewer than seven planets in the system, each roughly the same size as the Earth. They are named TRAPPIST-1b,c,d,e,f,g and h, with increasing distance from the central star.

Further observations have now been made, both from telescopes on the ground, including the nearly-complete SPECULOOS facility at ESO's Paranal Observatory, and from NASA's Spitzer Space Telescope and the Kepler Space Telescope.

A team of scientists led by Simon Grimm at the University of Bern in Switzerland have now applied very complex computer modelling methods to all the available data and have determined the planets' densities with much better precision than was possible before.

Simon Grimm explains how the masses are found: "The TRAPPIST-1 planets are so close together that they interfere with each other gravitationally, so the times when they pass in front of the star shift slightly. These shifts depend on the planets' masses, their distances and other orbital parameters. With a computer model, we simulate the planets' orbits until the calculated transits agree with the observed values, and hence derive the planetary masses."

Team member Eric Agol comments on the significance: "A goal of exoplanet studies for some time has been to probe the composition of planets that are Earth-like in size and temperature. The discovery of TRAPPIST-1 and the capabilities of ESO's facilities in Chile and the NASA Spitzer Space Telescope in orbit have made this possible - giving us our first glimpse of what Earth-sized exoplanets are made of!"

The measurements of the densities, when combined with models of the planets' compositions, strongly suggest that the seven TRAPPIST-1 planets are not barren rocky worlds. They seem to contain significant amounts of volatile material, probably water, amounting to up to 5% the planet's mass in some cases - a huge amount; by comparison the Earth has only about 0.02% water by mass!

"Densities, while important clues to the planets' compositions, do not say anything about habitability. However, our study is an important step forward as we continue to explore whether these planets could support life," said Brice-Olivier Demory, co-author at the University of Bern.

TRAPPIST-1b and c, the innermost planets, are likely to have rocky cores and be surrounded by atmospheres much thicker than Earth's. TRAPPIST-1d, meanwhile, is the lightest of the planets at about 30 percent the mass of Earth. Scientists are uncertain whether it has a large atmosphere, an ocean or an ice layer.

Scientists were surprised that TRAPPIST-1e is the only planet in the system slightly denser than Earth, suggesting that it may have a denser iron core and that it does not necessarily have a thick atmosphere, ocean or ice layer.

It is mysterious that TRAPPIST-1e appears to be so much rockier in its composition than the rest of the planets. In terms of size, density and the amount of radiation it receives from its star, this is the planet that is most similar to Earth.

TRAPPIST-1f, g and h are far enough from the host star that water could be frozen into ice across their surfaces. If they have thin atmospheres, they would be unlikely to contain the heavy molecules that we find on Earth, such as carbon dioxide.

"It is interesting that the densest planets are not the ones that are the closest to the star, and that the colder planets cannot harbour thick atmospheres," notes Caroline Dorn, study co-author based at the University of Zurich, Switzerland.

The TRAPPIST-1 system will continue to be a focus for intense scrutiny in the future with many facilities on the ground and in space, including ESO's Extremely Large Telescope and the NASA/ESA/CSA James Webb Space Telescope.

Astronomers are also working hard to search for further planets around faint red stars like TRAPPIST-1. As team member Michael Gillon explains: "This result highlights the huge interest of exploring nearby ultracool dwarf stars - like TRAPPIST-1 - for transiting terrestrial planets. This is exactly the goal of SPECULOOS, our new exoplanet search that is about to start operations at ESO's Paranal Observatory in Chile."


Related Links
European Southern Observatory
Lands Beyond Beyond - extra solar planets - news and science
Life Beyond Earth


Thanks for being there;
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 Monthly Supporter
$5+ Billed Monthly


paypal only
SpaceDaily Contributor
$5 Billed Once


credit card or paypal


EXO WORLDS
First Light for Planet Hunter ExTrA at La Silla
Garching, Germany (SPX) Jan 29, 2018
A new national facility at ESO's La Silla Observatory has successfully made its first observations. The ExTrA telescopes will search for and study Earth-sized planets orbiting nearby red dwarf stars. ExTrA's novel design allows for much improved sensitivity compared to previous searches. Astronomers now have a powerful new tool to help in the search for potentially habitable worlds. The newest addition to ESO's La Silla observatory in northern Chile, Exoplanets in Transits and their Atmospheres (E ... read more

Comment using your Disqus, Facebook, Google or Twitter login.



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

EXO WORLDS
Putting down roots in space

Celebrating 60 years of groundbreaking US space science

Russia to start offering spacewalks for tourists

Spinoff 2018 Highlights Space Technology Improving Life on Earth

EXO WORLDS
Genius or joker: Elon Musk flamethrowers spark controversy

SpaceX blasts off Luxembourg government satellite

Putin gives nod to creation of Russian super heavy-lift launch vehicle

Indra and Zero 2 Infinity are teaming up to forge a path to the stars

EXO WORLDS
Opportunity Celebrates 14 Years of Working on Mars

Mount Sharp 'Photobombs' Mars Curiosity Rover

NASA tests power system to support manned missions to Mars

European-Russian space mission steps up the search for life on Mars

EXO WORLDS
China's first X-ray space telescope put into service after in-orbit tests

China's first successful lunar laser ranging accomplished

Yang Liwei looks back at China's first manned space mission

Space agency to pick those with the right stuff

EXO WORLDS
Brexit prompts EU to move satellite site to Spain

Europe's space agency braces for Brexit fallout

Xenesis and ATLAS partner to develop global optical network

GomSpace signs deal for low-inclination launch on Virgin's LauncherOne

EXO WORLDS
Quantum control

Virtual reality goes magnetic

A frequency-doubling unit for transportable lasers

Pearly material for bendable heating elements

EXO WORLDS
Stellar embryos in dwarf galaxy contain complex organic molecules

First Light for Planet Hunter ExTrA at La Silla

A new 'atmospheric disequilibrium' could help detect life on other planets

Johns Hopkins scientist proposes new limit on the definition of a planet

EXO WORLDS
Europa and Other Planetary Bodies May Have Extremely Low-Density Surfaces

JUICE ground control gets green light to start development

New Year 2019 offers new horizons at MU69 flyby

Study explains why Jupiter's jet stream reverses course on a predictable schedule









The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - 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. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us.