Forum für Wissenschaft, Industrie und Wirtschaft

Hauptsponsoren:     3M 
Datenbankrecherche:

 

Hunt for Distant Planets Intensifies

20.02.2013
When astronomers discovered planet GJ 1214b circling a star more than 47 light-years from Earth in 2009, their data presented two possibilities. Either it was a mini-Neptune shrouded in a thick atmosphere of hydrogen and helium, or it was a water world nearly three times the size of Earth.

Along came Jacob Bean, now an assistant professor in astronomy & astrophysics at the University of Chicago, who used a new method called multi-object spectroscopy to analyze the planet’s atmosphere from large, ground-based telescopes. Aided by technology, Bean and his colleagues are surmounting the challenge of inferring the atmospheric composition of planets that were invisible to humans just a few years ago.

“We’re trying to distinguish whether it’s like the gas giants we know about, or something fundamentally different from what we’ve seen in our solar system — an atmosphere predominantly composed of water,” Bean said.

The search for exoplanets - planets beyond our own solar system - has taken off over the last decade, and is now a growing component of UChicago’s research agenda in astronomy. One estimate published in January calculated that our Milky Way galaxy alone contains at least 17 billion Earth-sized planets, with a vast potential for life-sustaining worlds. Pursuing the exoplanet search via complementary methods are Bean and Daniel Fabrycky, another assistant professor in astronomy & astrophysics.

Bean has received a 60-orbit allocation on the Hubble Space Telescope to continue his observations on GJ 1214b, a sign of the work’s importance. Previous HST studies of planetary atmospheres encompassed 10 to 20 orbits. Bean will use a technique called transmission spectroscopy to measure the chemical composition of the planet’s atmosphere with unprecedented precision.

A big prize

A definitive assessment of the planet’s atmosphere could lead to a larger prize: learning how to detect potential signs of alien life on a cosmically distant Earth twin. The atmospheric signature of life on an exoplanet presumably would contain some mixture of oxygen and various other gases.

Planetary scientists are conducting theoretical studies to narrow the range of possibilities.

“It’s interesting to note that all the instruments astronomers have used to study exoplanet atmospheres so far were never designed for that,” Bean said. “We’re using them in very unusual ways. We do what we can with what we have.”

But now Bean aims to build a system that is perfectly suited and well optimized to study exoplanet atmospheres, including that of GJ 1214b.

“The current data suggest an atmosphere predominately composed of water, but it’s not a definitive result yet,” Bean said. “There could be even more exotic scenarios possible that we’re not able to rule out.”

If GJ 1214b is a water world, “It would be very different than anything in our own solar system,” said Harvard University astronomy Professor David Charbonneau, whose team discovered the planet.

Deep questions

The search taps into some of modern science’s deepest questions: Are humans alone in the cosmos, and is our life-sustaining world unique? One of the earliest writers to speculate about exoplanets was the Italian philosopher and scientist Giordano Bruno, who was burned at the stake in 1600 for espousing beliefs that the Catholic Church deemed heretical.

In one prescient passage, Bruno wrote, “In space there are countless constellations, suns and planets; we see only the suns because they give light; the planets remain invisible, for they are small and dark. There are also numberless earths circling around their suns, no worse and no less than this globe of ours.”

Discoveries of new exoplanets have flowed like oil from a gushing wellhead in recent years. The number has topped 850 and continues to climb.

Starting in the 1990s, exoplanet hunters initially were only able to find giant, Jupiter-like gas planets because they were bigger and thus easier to find. “They were closer to their stars than Jupiter is from the sun, so we nicknamed them ‘hot Jupiters,’” Charbonneau said.

But in recent years, scientists began pursuing a new, more interesting goal: find planets that are more Earthlike. One major push along that front was the $600-million Kepler mission, launched in 2009. This mission, encompassing a 100-member science team, is conducting a survey of planets orbiting other sun-like stars.

“Kepler is on the cusp of finding small planets in the habitable zone around both sun-like and small stars,” Fabrycky said. “This is the goal of the mission, and it’s almost there.”

New research frontiers at UChicago

A Kepler research veteran, Fabrycky began his UChicago faculty appointment last October. Fabrycky precisely measures the timing of transits, the mini eclipses that planets cause as they pass in front of their stars. Timing inconsistencies in the transits often result from the gravitational influence of other planets.

So far Kepler has 105 confirmed planet discoveries to its credit, and has identified 2,740 planet candidates. As a postdoctoral scientist at the University of California, Santa Cruz, two years ago, Fabrycky was a member of a team that discovered six planets orbiting a single star called Kepler-11. “Kepler-11 is hanging on — for the moment — as the one with the most number of planet signals” among exoplanetary systems, Fabrycky said.

Bean and his colleagues have made the best observations of planetary atmospheres so far using the Hubble Telescope, the Spitzer Space Telescope, and, in Chile, the Very Large Telescope array and the twin Magellan Telescopes. But the planned Giant Magellan Telescope, of which UChicago is a founding partner, and the forthcoming James Webb Space Telescope should eclipse the capabilities of today’s observatories when they go into service late this decade.

The new telescopes will be able to do the same sort of exoplanetary atmospheric studies underway now, “but actually do it for the smaller planets that might even be habitable,” Charbonneau said.

Steve Koppes | Newswise
Further information:
http://www.uchicago.edu

More articles from Physics and Astronomy:

nachricht Quantum optics allows us to abandon expensive lasers in spectroscopy
22.11.2017 | Lomonosov Moscow State University

nachricht Nano-watch has steady hands
22.11.2017 | University of Vienna

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: Kleine Strukturen – große Wirkung

Innovative Schutzschicht für geringen Verbrauch künftiger Rolls-Royce Flugtriebwerke entwickelt

Gemeinsam mit Rolls-Royce Deutschland hat das Fraunhofer-Institut für Werkstoff- und Strahltechnik IWS im Rahmen von zwei Vorhaben aus dem...

Im Focus: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

Im Focus: Transparente Beschichtung für Alltagsanwendungen

Sport- und Outdoorbekleidung, die Wasser und Schmutz abweist, oder Windschutzscheiben, an denen kein Wasser kondensiert – viele alltägliche Produkte können von stark wasserabweisenden Beschichtungen profitieren. Am Karlsruher Institut für Technologie (KIT) haben Forscher um Dr. Bastian E. Rapp einen Werkstoff für solche Beschichtungen entwickelt, der sowohl transparent als auch abriebfest ist: „Fluoropor“, einen fluorierten Polymerschaum mit durchgehender Nano-/Mikrostruktur. Sie stellen ihn in Nature Scientific Reports vor. (DOI: 10.1038/s41598-017-15287-8)

In der Natur ist das Phänomen vor allem bei Lotuspflanzen bekannt: Wassertropfen perlen von der Blattoberfläche einfach ab. Diesen Lotuseffekt ahmen...

Im Focus: Ultrakalte chemische Prozesse: Physikern gelingt beispiellose Vermessung auf Quantenniveau

Wissenschaftler um den Ulmer Physikprofessor Johannes Hecker Denschlag haben chemische Prozesse mit einer beispiellosen Auflösung auf Quantenniveau vermessen. Bei ihrer wissenschaftlichen Arbeit kombinierten die Forscher Theorie und Experiment und können so erstmals die Produktzustandsverteilung über alle Quantenzustände hinweg - unmittelbar nach der Molekülbildung - nachvollziehen. Die Forscher haben ihre Erkenntnisse in der renommierten Fachzeitschrift "Science" publiziert. Durch die Ergebnisse wird ein tieferes Verständnis zunehmend komplexer chemischer Reaktionen möglich, das zukünftig genutzt werden kann, um Reaktionsprozesse auf Quantenniveau zu steuern.

Einer deutsch-amerikanischen Forschergruppe ist es gelungen, chemische Prozesse mit einer nie dagewesenen Auflösung auf Quantenniveau zu vermessen. Dadurch...

Im Focus: Leoniden 2017: Sternschnuppen im Anflug?

Gemeinsame Pressemitteilung der Vereinigung der Sternfreunde und des Hauses der Astronomie in Heidelberg

Die Sternschnuppen der Leoniden sind in diesem Jahr gut zu beobachten, da kein Mondlicht stört. Experten sagen für die Nächte vom 16. auf den 17. und vom 17....

Alle Focus-News des Innovations-reports >>>

Anzeige

Anzeige

IHR
JOB & KARRIERE
SERVICE
im innovations-report
in Kooperation mit academics
Veranstaltungen

IfBB bei 12th European Bioplastics Conference mit dabei: neue Marktzahlen, neue Forschungsthemen

22.11.2017 | Veranstaltungen

Zahnimplantate: Forschungsergebnisse und ihre Konsequenzen – 31. Kongress der DGI

22.11.2017 | Veranstaltungen

Tagung widmet sich dem Thema Autonomes Fahren

21.11.2017 | Veranstaltungen

 
VideoLinks
B2B-VideoLinks
Weitere VideoLinks >>>
Aktuelle Beiträge

Bakterien als Schrittmacher des Darms

22.11.2017 | Biowissenschaften Chemie

Ozeanversauerung schädigt Miesmuscheln im Frühstadium

22.11.2017 | Biowissenschaften Chemie

Die gefrorenen Küsten der Arktis: Ein Lebensraum schmilzt davon

22.11.2017 | Geowissenschaften