Posts Tagged ‘solar system’

Herschel/Planck New Launch Date Scheduled

By Bellatrix

The largest mirror ever to be launched into space now has a set launch date.  The European Space Agency’s Herschel Space Observatory and Planck Satellite are set to launch into space May 6th. . Together these two pieces of equipment should be bringing in lots of new and exciting information about our own solar system and distant galaxies.

Sir Frederick William Herschel was a German born British astronomer from the 18th and 19th century. He was most famous for discovering the planet Uranus and discovering infrared radiation.  The Herschel Space Observatory will be the first to cover the full far infrared and sub-millimeter telescope.  The large mirror measures in at 3.5 meters; it’s a novel and advanced concept using 12 silicon carbide petals brazed together into a single piece. It is one of the major technological highlights of the mission.  Herschel will be investigating a large array of astronomical objects including: galaxy formation in the early universe and galaxy evolution, star formation and its interaction with the interstellar medium, chemical composition of atmospheres and surfaces of solar system bodies, and molecular chemistry across the universe.  Sounds like it has it work cut out.

The Planck Satellite will be going up with Herschel Observatory.  The satellite is named after the famous German physicist Max Planck who is considered the founder of quantum theory.  The satellite was designed to observe the anisotropies of the cosmic microwave background radiation, or CMB, over the entire sky using high angular resolution.  The mission is meant to improve upon the data collected from the well-known WMAP mission and will be used to test theories of the early universe and the origin of cosmic structure. 

Herschel and Planck will start their journey in space on board an Ariane 5 departing from Europe’s Spaceport in Kourou, French Guiana. Final preparations for the launch are now being made such as fueling the two satellites and filling Herschel’s cryostat (a vessel used to maintain cryogenic temperatures) with helium.  Once launched the two satellites will separate and be put into separate orbits around the second lagrangian point of the earth-sun system, a distance of about 1.5 million km’s from Earth.  Both satellites are part of the European Space Agency’s Horizons 2000 Scientific Programme, which consisted of about 15 satellite or telescope projects over the last 20 years including such other projects as Cluster, Huygens, XMM-Newton, and others.

The launch of these two satellites/observatories is exciting. They are new and advanced pieces of technology aimed at answering some large questions in astronomy today.  And are a fine example of astronomy goals and projects outside of the US.  So for now we just have to keep our fingers crossed and hold our breath for a successful launch and problem free start up. 

Could life exist on Super-Earths?

By Evan Finnes

The search for extraterrestrial life within our solar system has mainly been focused on Mars, and there has been speculation that some the moons of the outer solar system may also be a good place to look for life. Outside of our solar system, planet hunters and astrobiologists have been searching for Earth-like planets to help answer one of mankind’s most profound questions, “are we alone?” To date, no such planets have been discovered, so a team of scientists have now set their sights on a relatively abundant group of extrasolar planets known as “super-Earths”.

The term “super-Earth” is slightly misleading because the only thing that these planets have in common with the Earth is the fact that they are terrestrial. A super-Earth is typically classified as a terrestrial planet with a mass of 5 to 10 Earth masses. Thus far, Super Earths have not been found within the habitable zone of their host star, with orbits much too far or much too close to sustain life as we know it. The super-Earths with orbits far from their host star are the places that astrobiologists now believe could harbor some form of life.

It is estimated that one-third of all solar systems contain super-Earths, and some scientists believe that it may be possible to find some that have liquid water either on the surface, or below a thick layer of ice. This water could theoretically exist on a super-Earth if one of three conditions were met. 1) If the planet had a thick enough atmosphere it may be possible that enough solar radiation could be by greenhouse gases to prevent water from completely freezing. 2) If the planet was massive enough or young enough, there may still be enough primordial heat available to sustain some amount of liquid water.

Currently, the best technique for discovering super-Earths is by using gravitational microlensing. This phenomena occurs when an object in the foreground has enough mass, its gravitational field will bend the incoming light of a much more distant object. This results in the magnification of the distant object, no matter how faint it may seem.

It is not unfathomable to predict that an extrasolar super-Earth outside of its host stars habitable zone could contain water, at least as ice. Much of the ice in our own solar system is located outside of the habitable zone. There is no super-Earth in our solar system, but there are icy bodies that could contain liquid oceans. It is hypothesized that Jupiter’s moon, Europa, may have enough heat due to tidal flexing to permit a liquid ocean.

Traveling amongst the stars and exploring extrasolar planets is unfortunately not in the near future, but we can test hypothesis such as this one by exploring the planets within our solar system, and isn’t it about time we send a probe to Europa?

ExtraSolar CO2

By Evan Finnes

For the first time carbon dioxide has been found in the atmosphere of a planet outside of our own solar system. This is an important discovery because carbon dioxide is one the chemicals we would expect to find on a planet that harbors life, the other chemicals include: oxygen, water, and methane. Water vapor, along with carbon monoxide has previously been detected in the planet’s atmosphere.

Unfortunately, the discovery of carbon dioxide on this planet cannot be correlated to life. This Jupiter sized planet, which is located 63 light years from Earth, is known as HD 189733b. It has an orbital period of about 2.2 days and has a scorching surface temperature of about 1117 K. The close proximity of the planet to its host star may be responsible for the formation of carbon dioxide in the planet’s atmosphere. As the planet orbits, relatively close to its sun, it receives a high dosage of ultraviolet radiation. This radiation may have stripped apart other chemicals in the planet’s atmosphere while creating new chemicals, such as carbon dioxide.

The carbon dioxide was detected by analyzing the infrared spectrum of the planet. Because HD 189733b lies so close to its host star, the combined spectrum of the star/planet system had to first be analyzed and recorded. Scientists then waited for the planet to disappear behind its host star, so that the suns individual spectrum could be recorded. To obtain the planets individual spectrum, the spectrum of the star was subtracted from the star/planet system.

French astronomers discovered HD 189733b, in the constellation Vulpecula, on Oct. 5, 2005 by observing the transit of the planet across its host star. Since its discovery, the planet has reached a number of milestones. It was the first extrasolar planet to be mapped, it was the first found to contain water vapor and methane (which probably react in the high temperatures to form the carbon monoxide), and now it is the first exosolar planet known to contain carbon dioxide.

This discovery confirms our ability to detect the chemical compositions of planets outside of our solar system. If, and hopefully when, an Earth-like is discovered, analyzing the spectral signatures will be more difficult due to the small sizes of terrestrial planets. As we continue to develop our techniques by recording the spectral signatures of Jupiter-like planets, and super Earths, there should be little doubt that we will be ready to analyze the atmosphere of an Earth or Mars sized planet when the discovery occurs, bringing us one step closer to eventually detecting life on another planet.

A Younger Version of Our Solar System

By Bellatrix

New information about a neighboring star has shed some light on our theories of solar system formation and given hope to terrestrial planet hunters. The near by star Epsilon Eridani has features very similar to our own solar system, it is however much younger than our own system, perhaps giving us a glimpse to how our solar system might have looked in its very early stages.

The star itself is about 10.5 light years away. It is the third brightest star seen with the naked eye. The star is a K2 spectral type star; it is slightly smaller and less massive than the sun. It is thought to be less than a billion years old, where our sun is close to 5 billion years old. Because of it’s young age it has a much higher level of magnetic activity than the sun and a stellar wind about 30 times as strong.

Recently, using the Spitzer Space Telescope, astronomers have identified two areas of rocky rings, or asteroid belts, just like our solar system. It has an inner asteroid belt at an equivalent distance from its star as our asteroid belt to the sun. An outer asteroid belt is also present at about the position where our Uranus is. This outer belt contains about 20 times more material than the inner belt. A third ring of icy materials is set out about 35 to 100 AU from the star, very similar to our Kuiper Belt but with about 100 times more material. This extra material makes sense, given the systems age. Our solar system is much older and thus has had more time for collisions to take place and either destroy material or send it out of orbit.

Spitzer also noticed large gaps in these rings. The most logical explanation for these gaps is the presence of planets. Astronomers predict at least three planets with masses between that of Neptune and Jupiter, and another possible smaller planet may lie near the innermost ring. These gaps and the closeness of this star, plus evidence from other planet hunting techniques such as observing radial velocities, makes this star high on the list of planet hunters trying to find earth like planets, and even possibly life. With all the similarities noticed thus far between the two systems, one might think it surprising not to find smaller rocky planets in the inner part of the system.

Studying this system is exciting ad enlightening for astronomers. Seeing that our solar system is not totally unique means that our theories about how solar systems for may not be completely off base. Also, studying this solar system more intensely may show us things about our early solar system we wouldn’t have otherwise known. As the resolving power of our telescopes improve new discoveries from this system should be something to watch out for.