Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Hubble Finds Three Surprisingly Dry Exoplanets

25.07.2014

Astronomers using NASA's Hubble Space Telescope have gone looking for water vapor in the atmospheres of three planets orbiting stars similar to the sun -- and have come up nearly dry.

The three planets, known as HD 189733b, HD 209458b, and WASP-12b, are between 60 and 900 light-years away from Earth and were thought to be ideal candidates for detecting water vapor in their atmospheres because of their high temperatures where water turns into a measurable vapor.


This is an artistic illustration of the gas giant planet HD 209458b in the constellation Pegasus. To the surprise of astronomers, they have found much less water vapor in the hot world’s atmosphere than standard planet-formation models predict.

Image Credit: NASA, ESA, G. Bacon (STScI) and N. Madhusudhan (UC)

These so-called “hot Jupiters” are so close to their star they have temperatures between 1,500 and 4,000 degrees Fahrenheit, however, the planets were found to have only one-tenth to one one-thousandth the amount of water predicted by standard planet-formation theories.

"Our water measurement in one of the planets, HD 209458b, is the highest-precision measurement of any chemical compound in a planet outside our solar system, and we can now say with much greater certainty than ever before that we've found water in an exoplanet," said Nikku Madhusudhan of the Institute of Astronomy at the University of Cambridge, England. "However, the low water abundance we have found so far is quite astonishing."

Madhusudhan, who led the research, said that this finding presents a major challenge to exoplanet theory. "It basically opens a whole can of worms in planet formation. We expected all these planets to have lots of water in them. We have to revisit planet formation and migration models of giant planets, especially “hot Jupiters,” and investigate how they're formed."

He emphasizes that these results may have major implications in the search for water in potentially habitable Earth-sized exoplanets. Instruments on future space telescopes may need to be designed with a higher sensitivity if target planets are drier than predicted. "We should be prepared for much lower water abundances than predicted when looking at super-Earths (rocky planets that are several times the mass of Earth)," Madhusudhan said.

Using near-infrared spectra of the planets observed with Hubble, Madhusudhan and his collaborators estimated the amount of water vapor in each of the planetary atmospheres that explains the data.

The planets were selected because they orbit relatively bright stars that provide enough radiation for an infrared-light spectrum to be taken. Absorption features from the water vapor in the planet's atmosphere are detected because they are superimposed on the small amount of starlight that glances through the planet's atmosphere.

Detecting water is almost impossible for transiting planets from the ground because Earth's atmosphere has a lot of water in it, which contaminates the observation. "We really need the Hubble Space Telescope to make such observations," said Nicolas Crouzet of the Dunlap Institute at the University of Toronto and co-author of the study.

The currently accepted theory on how giant planets in our solar system formed, known as core accretion, states a planet is formed around the young star in a protoplanetary disk made primarily of hydrogen, helium, and particles of ices and dust composed of other chemical elements. The dust particles stick to each other, eventually forming larger and larger grains. The gravitational forces of the disk draw in these grains and larger particles until a solid core forms. This then leads to runaway accretion of both solids and gas to eventually form a giant planet.

This theory predicts that the proportions of the different elements in the planet are enhanced relative to those in its star, especially oxygen, which is supposed to be the most enhanced. Once the giant planet forms, its atmospheric oxygen is expected to be largely encompassed within water molecules. The very low levels of water vapor found by this research raise a number of questions about the chemical ingredients that lead to planet formation.

"There are so many things we still don't know about exoplanets, so this opens up a new chapter in understanding how planets and solar systems form," said Drake Deming of the University of Maryland, who led one of the precursor studies. "The problem is that we are assuming the water to be as abundant as in our own solar system. What our study has shown is that water features could be a lot weaker than our expectations."

The findings are published July 24 in The Astrophysical Journal Letters.

The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA's Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, Inc., in Washington.

For images and more information about Hubble, visit:

http://www.nasa.gov/hubble

and

http://hubblesite.org/news/2014/36 

J.D. Harrington
Headquarters, Washington
202-358-5241
j.d.harrington@nasa.gov

Ray Villard
Space Telescope Science Institute, Baltimore, Md.
410-338-4514
villard@stsci.edu

Ray Villard | Eurek Alert!

Further reports about: Astronomy Earth Flight Hubble Jupiters NASA Space Telescope atmosphere measurement temperatures

More articles from Physics and Astronomy:

nachricht Study offers new theoretical approach to describing non-equilibrium phase transitions
27.04.2017 | DOE/Argonne National Laboratory

nachricht SwRI-led team discovers lull in Mars' giant impact history
26.04.2017 | Southwest Research Institute

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Fighting drug resistant tuberculosis – InfectoGnostics meets MYCO-NET² partners in Peru

28.04.2017 | Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

 
Latest News

Wireless power can drive tiny electronic devices in the GI tract

28.04.2017 | Medical Engineering

Ice cave in Transylvania yields window into region's past

28.04.2017 | Earth Sciences

Nose2Brain – Better Therapy for Multiple Sclerosis

28.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>