Advanced Search
Astrobiology Magazine Facebook  Astrobiology Magazine Twitter
Extrasolar Life
Simulations suggest the wide variety of outer planetary systems that planetesimal disks can produce. The outer solar system is shown for comparison (a). The simulated planetary systems that resulted from these 11 experimental runs range from having just one (b) to as many as seven (f) outer planets of varying mass (indicated above each planet in Earth masses). The different outcomes depend on the initial arrangement
of planetesimals and the chaotic interactions between them. (Adapted from Levinson et al. 1998.)
Viewed: 1148 times
Studies of extrasolar systems offer astronomers increasing opportunity to test their ideas about planet formation. The three innermost planets of star 55 Cancri, for example, have orbits smaller than that of Mercury. These three planets are separated from a much more massive world by a region of apparent stability, which is predicted to harbor another planet. This region encompasses the star´ habitable zone, where surface temperatures would allow a suitable planet to support liquid water. The number above each planet in the bottom panel shows its minimum mass, expressed in Earth masses.
Viewed: 1178 times
Some 4.6 billion years ago, before Earth existed, the Sun was surrounded by a disk of gas and dust, from which countless small bodies were forming. Most of these "planetesimals" coalesced into larger planetary embryos, which grew larger still to become the eight planets of the solar system. Why eight? There is nothing special about the number. Chaotic encounters between planetesimals early on led to a system with enough large bodies to sweep up most of the smaller ones. Computer simulations suggest that such encounters could as readily have ended up with fewer or more planets–”but not too many. The present configuration
of the solar system is filled nearly to capacity, and additional planets would be dynamically unstable. (Artist´ rendering of a hypothetical
planetary system in the making by T. Pyle, courtesy of NASA/JPL-Caltech.)
Viewed: 1177 times
The Arecibo message was composed of the digital bits "one" and "zero". A "one" was represented by an "on" radio pulse; a "zero" was represented by an "off" radio pulse. (The message starts: 000000101010100....). This picture was generated by arranging the 1679 bits into 23 columns of 73 rows, 23 and 73 being the two prime numbers, which, when multiplied together, equal 1679. A box representing a "one" is black, while a box representing "zero" is white.
Viewed: 1044 times
The Parkes Radio Telescope in New South Wales, Australia. SETI's Project Phoenix conducted observations here from February to June of 1995.
Viewed: 1195 times

Researchers have demonstrated the formation of microscopic strands of helical
structures in plasma clouds. The researchers say that these structures undergo
changes that are normally associated with biological molecules like DNA and proteins
- such as dividing and forming copies of the original structure.
Credit: Tsytovich, V.N. et al. 2007
Viewed: 1077 times
This artist's impression shows what the disk of debris may look like
around the white dwarf star GD 362.
Credit: Gemini Observatory/Jon Lomberg.
Viewed: 764 times
This images shows the relative size of GD 362 compared to Saturn and the
Credit: Gemini Observatory/Jon Lomberg
Viewed: 763 times
In the foreground is the Teton Mountain Range of Wyoming, USA. On the far left, vast clouds of bright stars and dark dust are visible in the nearly vertical plane of our Milky Way Galaxy. On the left, just to the left of the southernmost Teton peak, the planet Jupiter is visible. Near the image center is the bright star Arcturus. Credit & Copyright: Wally Pacholka (; Image Processing: Tony Hallas.
Viewed: 1571 times
The solar system's habitable zone.
Viewed: 757 times

This digitally enhanced double-exposure was taken in May 2003 over the Kofa Mountains in Arizona, USA. Dark dust, millions of stars, and bright glowing red gas highlight the plane of our Milky Way Galaxy. Photo Credit: Richard Payne (Arizona Astrophotography)
Viewed: 1258 times
This image from Spitzer shows the stellar nursery, called NGC 1333, that contains
the "steamy" young solar system, called NGC 1333-IRAS 4B.
Credit: NASA/JPL-Caltech/ Harvard-Smithsonian CfA
Viewed: 983 times
Stars in the globular cluster NGC 6397. Credit: Hubble Space Telescope/ESA/NASA.
Viewed: 690 times
Stars in the globular cluster NGC 290. Credit: Hubble Space Telescope/ESA/NASA
Viewed: 869 times
Artist´ illustration of what plants may look like on different planets. Credit: Caltech/Doug Cummings.
Viewed: 805 times

An artist's concept of plant life on a planet that orbits a different class of star. Image Credit:
NASA/JPL-Caltech/T. Pyle (SSC).
Viewed: 1009 times
The orbits of several extrasolar planets compared to Earth's orbit. Many of the gas giant extrasolar planets orbit less than 1 AU from their host star, and have highly elliptical orbits.
Viewed: 860 times
This is an artist's concept of an Earthlike planet around another star.
Credit: NASA JPL
Viewed: 1043 times
Astronomers have calculated the diameters of various types of planets
given certain compositions and masses. This image shows the relative
sizes of six different kinds of planets with different compositions, and
depending on whether they have the same mass as Earth, or five times the
mass of Earth. Note that the 5-Earth-mass planets are larger than their
1-Earth-mass counterparts, but they are not five times larger due to the
gravitational compression that occurs when a planet's mass is increased.
The planets are shown silhouetted against the Sun, as if they are
transiting planets seen from afar.
Credit: Marc Kuchner/NASA GSFC.
Viewed: 726 times
These theoretical models plot a planet's size and mass given a certain
composition. Future observations might be able to distinguish a pure
water planet from a pure iron planet, but might have difficulty
distinguishing a carbon planet from a silicate planet, for example.
Click here to download an unlabeled version of this image.
Credit: Marc Kuchner/NASA GSFC.
Viewed: 976 times

The Smith Telescope at the McDonald Observatory has a 2.7-meter mirror and was the
third largest in the world when it was built in the late 1960's.
Credit: McDonald Observatory
Viewed: 728 times
HIP 56948 is located 200 light-years away from Earth in the constellation Draco.
Credit: Tim Jones/McDonald Obs./UT-Austin
Viewed: 723 times
This infrared image of the Pleiades star cluster –“ or Seven Sisters –“ was captured
by NASA's Spitzer Space Telescope. The star HD 23514 is located in Pleiades, some
400 light years away from Earth.
Credit: NASA/JPL-Caltech/J. Stauffer (SSC/Caltech)
Viewed: 794 times
This artist's rendering shows what the environment around HD 23514 might look like.
Heat radiating from dust around the star indicates that there may have been a recent
collision between two large, rocky bodies - similar to the collision that formed the
Earth's Moon.
Credit: Gemini Observatory/Lynette Cook
Viewed: 980 times
The Lyot Project will be attached to the Hale Telescope at the Palomar
Observatory in California.
Credit: NASA
Viewed: 594 times

Ben R. Oppenheimer, the principal investigator of the Lyot Project,
makes adjustments to the coronagraph on a work bench.
Credit: NASA
Viewed: 571 times
The first ground-based detection of an extrasolar planet's atmosphere was performed
using the Hobby-Eberly Telescope (HET) at the McDonald Observatory.
Credit: Marty Harris/McDonald Observatory.

Viewed: 724 times
NASA's Kepler Mission will survey our region of the Milky Way galaxy to detect
hundreds of Earth-sized and smaller planets near the habitable zone of their parent
stars. Currently, the mission is set for launch in 2009.
Credit: NASA
Viewed: 762 times
Arecibo Radio Telescope
Viewed: 650 times

SETI@home Chief Scientist, Dan Werthimer (right), and David Anderson, Project Leader (left).
Credit:Planetary society
Viewed: 645 times

The study simulated planets with masses as much as 10 times that of Earth. Planets
larger than this have the potential to gather gas as they form and become more like
Neptune rather than rocky and 'Earth-like'. The Voyager 2 spacecraft captured this
image of Neptune, the fourth of our Solar System's gas giants.
Credit: NASA/JPL/Caltech
Viewed: 728 times
Our solar system´ habitable zone, which is where the temperature is suitable for liquid water. Credit: NASA
Viewed: 588 times
An artist´ impression of Gliese 876 d. Frozen planets in this system could harbor life. Credit: Trent Schindler and the National Science Foundation.
Viewed: 687 times
This illustration shows the dusty disk around the small star FN Tau.
Because the mass of FN Tau is low, the disk is actually thicker in areas
further away from the central star.
Credit: National Astronomical Observatory of Japan
Viewed: 572 times
The CIAO instrument on Japan's Subaru Telescope was used to capture this
infrared image of the disk surrounding FN Tau. The star itself, located
in the center of the disk, is blocked by the coronagraph mask.
Credit: National Astronomical Observatory of Japan
Viewed: 725 times

The 8.2 meter Subaru Telescope is operated by the National Astronomical
Observatory of Japan, and is located atop Mauna Kea on the island of
Credit: University of Hawaii
Viewed: 691 times
This artist's concept shows a very young star encircled by a disk of gas
and dust, the raw materials from which rocky planets such as Earth are
thought to form.
Credit: NASA/JPL-Caltech
Viewed: 826 times
This plot of infrared data shows the signatures of water vapor and
simple organic molecules in the disk of gas and dust surrounding a young
Credit: NASA/JPL-Caltech
Viewed: 708 times
This image shows the discovery of KH 15D as captured by the Wesleyan 0.6
m telescope. KH 15 D is a variable star found in the young cluster NGC
Credit: Wesleyan University/Van Vleck Observatory
Viewed: 695 times
Artist's impression of the extrasolar planet HD 189733b, now known to
have methane and water.
Credit: Credit: ESA, NASA and G. Tinetti (University College London, UK
& ESA)
Viewed: 614 times

A wide star field image of the region around HD 189733b. The star HD
189733 is located in the centre, just to the left of the planetary
nebula Messier 27.
Credit: NASA, ESA, and the Digitized Sky Survey 2. Acknowledgment:
Davide De Martin (ESA/Hubble)
Viewed: 658 times
TESS will be used to detect planets as they transit in front of their parent stars.
Credit: Spaceref
Viewed: 677 times
Astronomers are developing a new device that may be the first to spot
Earth-like planets, like the hypothetical world with two moons shown in
this artist's concept.
Credit: David A. Aguilar (Harvard-Smithsonian Center for Astrophysics)
Viewed: 638 times
NASA´ Terrestrial Planet Finder is one of several instruments intended to detect planets around other stars. If Watson´ model is correct, even if some of those planets turn out to be Earth-like, they´re unlikely to host intelligent life.
Credit: NASA/JPL.
Viewed: 765 times
The host star of GJ 436c is an 11th magnitude red dwarf and is estimated to have a
radius that is about 42% of the Sun's.

Viewed: 630 times

Experimental data from a NIST "gap-toothed" frequency comb that are
false colored to indicate the range from low power (red) to high power
(blue). The comb is specially designed for astronomy. Each "tooth" is a
precisely known frequency, and the teeth are widely separated (by 20
gigahertz) in comparison to a standard comb.
Credit: M. Kirchner & S. Diddams/NIST
Viewed: 550 times
The Low Frequency Array (LOFAR) consists of about 25,000 low-cost sensors (antennas, geophones and more) that will receive signals from space.
Credit: LOFAR
Viewed: 507 times
The LOFAR array uses both low band and high band (pictured above) antennas. Electronic signals from the antennas are digitized and then sent to a central processor. Signals are combined using software to emulate a conventional antenna.
Credit: LOFAR
Viewed: 698 times
Series of images showing the Moon transiting Earth, captured by NASA's EPOXI spacecraft.
Credit: Donald J. Lindler, Sigma Space Corporation/GSFC; EPOCh/DIXI Science Teams
Viewed: 454 times
View of crescent Earth from space. A glint of sunlight (marked with yellow lines) appears just west of the Galapagos and South America. Photo Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
Viewed: 481 times

First   Prev |   Pages : 1 2 3 4   | Next   Last  
  Back to List of Albums

About Us
Contact Us
Podcast Rss Feed
Daily News Story RSS Feed
Latest News Story RSS Feed
Learn more about RSS
Chief Editor & Executive Producer: Helen Matsos
Copyright © 2014,