AbSciCon!
So as it turns out, there are a lot of other people interested in the search for extra-terrestrial life. Who knew, right? So many people, in fact, that there's an entire convention for it. The Astrobiology Science Conference, of AbSciCon, will be hosted in Atlanta, Georgia in mid April. I wish I could go. Perhaps next year?
When discussing what exactly kind of research I wanted to do, my adviser Dr. Canalizo recommended speaking with Dr. Lyons here at UCR. Unfortunately no one in the Astronomy department is doing research on anything within our solar system or Astrobiology. Dr. Lyons is part of the Geology/Biogeochemistry department, and one of his projects is to study early Earth conditions to see exactly what happened to make it viable for life. Bingo! Sign me up for that! While my work now isn't exactly glamorous (I take small rocks and use a machine to turn them into powder), eventually I will get to work on more interesting things. Plus, I knew I'd be way more interested in hands-on experimental research rather than theoretical. So my plan is to work my ass off until next year, and pray to the gods of grants to get funding for the trip.
Thursday, March 22, 2012
Water World!
http://www.spacetelescope.org/news/heic1204/
So Water World is real, and it was discovered in 2009 by the MEarth Project. What's oh-so-special about this exoplanet is that it's larger than Earth, hotter than Earth, but less dense than Earth, which would suggest a much higher percentage of water, and less rock.
Water World!
The creatively named GJ 1214b was found while searching for Earth-like planets outside our solar system (in Star Trek lingo, this would be Class M planet). GJ 1214b was nice enough to pass in front of its star within our plane of view, and has a transit of 38 hours. And since astronomers are so clever, they were able to figure out the size of the planet, which has a radius 2.7 times that of Earth's, and a mass of 6.7 Earths. Due to the very short transit, this would mean a very close orbit. And due the the very close orbit, this planet is HOT! About 230 C! So while life is not likely happening now, it IS very interesting to find a planet with such a large amount of water.
Astronomers were able to detect water on this planet due to the wavelength absorption of light as it passes in front of the star. The absorption rates fall in line the best with water, and not only that, but its atmosphere could be up to 50% water. Since the size and mass is known, the density computed for GJ 1214b is about 2 grams per cubic centimeter. This supports the idea that it is made up of mostly water, as it is much less dense than Earth (5.5 g/c^3). Water of course has a density of 1 g/c^3.
Due to it's large mass, and thick atmosphere, pressure on GJ 1214b would be pretty high. In space where there is no pressure, water can boil even at temperatures that would mean freezing on Earth. With enough pressure, it was suggested that there may even be materials like "hot ice". How weird is that?
It is theorized that GJ 1214b was formed much farther out from its star and then migrated closer, passing through the habitable zone. This would have meant the melting of the water ice, and temperatures very similar to Earth. It is not known, however, how long it was in that magical zone. Could life has started? Maybe.
So Water World is real, and it was discovered in 2009 by the MEarth Project. What's oh-so-special about this exoplanet is that it's larger than Earth, hotter than Earth, but less dense than Earth, which would suggest a much higher percentage of water, and less rock.
Water World!
The creatively named GJ 1214b was found while searching for Earth-like planets outside our solar system (in Star Trek lingo, this would be Class M planet). GJ 1214b was nice enough to pass in front of its star within our plane of view, and has a transit of 38 hours. And since astronomers are so clever, they were able to figure out the size of the planet, which has a radius 2.7 times that of Earth's, and a mass of 6.7 Earths. Due to the very short transit, this would mean a very close orbit. And due the the very close orbit, this planet is HOT! About 230 C! So while life is not likely happening now, it IS very interesting to find a planet with such a large amount of water.
Astronomers were able to detect water on this planet due to the wavelength absorption of light as it passes in front of the star. The absorption rates fall in line the best with water, and not only that, but its atmosphere could be up to 50% water. Since the size and mass is known, the density computed for GJ 1214b is about 2 grams per cubic centimeter. This supports the idea that it is made up of mostly water, as it is much less dense than Earth (5.5 g/c^3). Water of course has a density of 1 g/c^3.
Due to it's large mass, and thick atmosphere, pressure on GJ 1214b would be pretty high. In space where there is no pressure, water can boil even at temperatures that would mean freezing on Earth. With enough pressure, it was suggested that there may even be materials like "hot ice". How weird is that?
It is theorized that GJ 1214b was formed much farther out from its star and then migrated closer, passing through the habitable zone. This would have meant the melting of the water ice, and temperatures very similar to Earth. It is not known, however, how long it was in that magical zone. Could life has started? Maybe.
a vacation to Europa
http://blog.eag.eu.com/new-worlds-new-perspectives/life-seas-europe/
While not exactly a winter ski resort, Europa does have its own attractions. Also known as Jupiter II, Europa is perhaps the most viable candidate for extra terrestrial life in our solar system.
I can almost see the cabins now.
Europa was discovered in 1610 by Galileo Galilei, but it wasn't until the Galileo telescope, and the Voyagers, that we were able to get a much more detailed look. Europa is covered in lineae: deep, dark cracks along its icy surface. This suggests a softer, and very likely liquid water layer underneath its crust. And of course, where there's liquid water, there's a very good chance of life in some form.
Its surface is very cold, ranging from about 80K to 120K, and the radiation level here is high enough to kill humans. But the surface isn't where the magic is happening. Thought to be warmed by thermal vents and stretching due to Jupiter's gravity, the possible liquid water ocean could be a toasty (relatively speaking) 270K.
primordial soup?
Biogeochemists have been modelling Europa's ocean to try to see what exactly is going on over there (on a side note, this makes me very happy to work in a Biogeochemistry lab here at UCR, under Dr. Lyons). So far it seems agreed on that Europa could support a "putative chemoautotrophic biomass", but due to the very unlikelihood of there being any photosynthesis to speak of, life would most likely be very small, and very slow to reproduce.
It is very unfortunate that due to lack of funding (BIG surprise there), many of the Europan projects have been cancelled. My hope is to some day work on the Europa Jupiter System Mission, if that doesn't too get cancelled. The EJSM, a joint NASA/ESA project, will be an orbital/fly by mission scheduled for launch in 2020 (hopefully I'll have my PhD by then). This mission won't touch down on the surface, or drill through the crust, but it will be an invaluable source of new data. I just wish we will be able to crack Europa's crust in my lifetime.
While not exactly a winter ski resort, Europa does have its own attractions. Also known as Jupiter II, Europa is perhaps the most viable candidate for extra terrestrial life in our solar system.
I can almost see the cabins now.
Europa was discovered in 1610 by Galileo Galilei, but it wasn't until the Galileo telescope, and the Voyagers, that we were able to get a much more detailed look. Europa is covered in lineae: deep, dark cracks along its icy surface. This suggests a softer, and very likely liquid water layer underneath its crust. And of course, where there's liquid water, there's a very good chance of life in some form.
Its surface is very cold, ranging from about 80K to 120K, and the radiation level here is high enough to kill humans. But the surface isn't where the magic is happening. Thought to be warmed by thermal vents and stretching due to Jupiter's gravity, the possible liquid water ocean could be a toasty (relatively speaking) 270K.
primordial soup?
Biogeochemists have been modelling Europa's ocean to try to see what exactly is going on over there (on a side note, this makes me very happy to work in a Biogeochemistry lab here at UCR, under Dr. Lyons). So far it seems agreed on that Europa could support a "putative chemoautotrophic biomass", but due to the very unlikelihood of there being any photosynthesis to speak of, life would most likely be very small, and very slow to reproduce.
It is very unfortunate that due to lack of funding (BIG surprise there), many of the Europan projects have been cancelled. My hope is to some day work on the Europa Jupiter System Mission, if that doesn't too get cancelled. The EJSM, a joint NASA/ESA project, will be an orbital/fly by mission scheduled for launch in 2020 (hopefully I'll have my PhD by then). This mission won't touch down on the surface, or drill through the crust, but it will be an invaluable source of new data. I just wish we will be able to crack Europa's crust in my lifetime.
Wednesday, March 21, 2012
the world through quasar-lensed glasses
Quasars, or quasi-stellar radio sources, are the brightest known objects in the universe. The brightest known quasar has an absolute magnitude of -32.2 when it was discovered in 1998. However more recent data from Keck and Hubble show that the quasar APM 08279+5255 is gravitationally lensed, making it appear 10 times brighter than it actually is.
But what exactly are quasars? It is thought that they are a type of early, active galaxy, surrounding a super massive black hole. Their extreme brightness is due to the accretion disk of black holes that they surround, which can convert a whopping 10% of matter into energy. By comparison, proton-proton fusion converts about 0.7% of matter into energy. Because of their massive consumption (to sustain a luminosity of 10^40 watts would requite a consumption of about ten suns a year), quasars are thought to have been much more common in the early universe. The oldest/farthest detected quasar has a redshift of 7.085, meaning it was formed about 700 million years after the Big Bang. It is thought that after a quasar "burns out", it settles and forms a regular galaxy. Some astronomers even think that most galaxies once hosted quasars, even our own Milky Way.
Their extreme luminosity and distance of quasars makes it very hard to study their host galaxies. Of course, there are ways to get around that. Quasars cause gravitational lensing on their host galaxies, and that can be used to detect their mass.
http://www.nasa.gov/mission_pages/hubble/science/quasar-lens.html#
Einstein's General Theory of Relativity predicted gravitational lensing, and was observationally confirmed in 1979 by the first images of a double quasar. Lensing can cause double, triple or even quadruple images of the same quasar.
picture of the Einstein Cross
A team of astronomers using the Hubble telescope will be putting together a directory of "quasar-lenses" to compare masses of galaxies with quasars to those without.
But what exactly are quasars? It is thought that they are a type of early, active galaxy, surrounding a super massive black hole. Their extreme brightness is due to the accretion disk of black holes that they surround, which can convert a whopping 10% of matter into energy. By comparison, proton-proton fusion converts about 0.7% of matter into energy. Because of their massive consumption (to sustain a luminosity of 10^40 watts would requite a consumption of about ten suns a year), quasars are thought to have been much more common in the early universe. The oldest/farthest detected quasar has a redshift of 7.085, meaning it was formed about 700 million years after the Big Bang. It is thought that after a quasar "burns out", it settles and forms a regular galaxy. Some astronomers even think that most galaxies once hosted quasars, even our own Milky Way.
Their extreme luminosity and distance of quasars makes it very hard to study their host galaxies. Of course, there are ways to get around that. Quasars cause gravitational lensing on their host galaxies, and that can be used to detect their mass.
http://www.nasa.gov/mission_pages/hubble/science/quasar-lens.html#
Einstein's General Theory of Relativity predicted gravitational lensing, and was observationally confirmed in 1979 by the first images of a double quasar. Lensing can cause double, triple or even quadruple images of the same quasar.
picture of the Einstein Cross
A team of astronomers using the Hubble telescope will be putting together a directory of "quasar-lenses" to compare masses of galaxies with quasars to those without.
Arecibo
The Arecibo Observatory is the largest single-aperture telescope in the world. Completed in 1963 in Puerto Rico, its spot was chosen due to a very conveniently placed karst sinkhole. Its dish is 1000 feet (305 m) in diameter, and is spherical rather than parabolic. The advantage of having a spherical dish as opposed to a parabolic one is due to the fact that the error of a spherical dish is the same in every direction. A parabolic reflector can only see in one direction very well, vastly limiting its range. A spherical reflector also permits the telescope to employ three areas of research: radio astronomy, aeronomy, and radar astronomy (within the solar system).
Its design originally included a tower smack dab in the center of the dish, but was later scrapped for a suspended feed for obvious reasons. This also allowed for greater mobility, and protection from harsh weather. The idea came from Helias Doundoulakis, who was granted a U.S. Patent for the idea. When it was completed, Arecibo's surface was covered in wire mesh, and had a maximum operation frequency of about 500 MHz. It was updated in 1974, replacing the wire mesh with individually adjustable aluminum panels, increasing the maximum operation frequency by ten fold. Upgraded again in 1997, the aluminum panels were replaced with a Gregorian reflector (using concave parabolic and elliptical mirrors) system, and now the maximum operating frequency can reach 10 GHz. A new transmitter was also installed.
We have Arecibo to thank for many new astronomical discoveries over the past 50 years. Less than a year after it was completed, it was determined the rotation rate of Mercury was 59 days, not 88 days as it was thought to be. It helped provide evidence for neutron stars. In 1968, the Crab Pulsar was found to have a periodicity of 33 milliseconds. The first binary pulsar was discovered in 1974 using Arecibo. In 1982 the first millisecond pulsar PSR B1937+21 was discovered, which spins at a rate of 642 times per second. Arecibo was also the first telescope to directly image an asteroid. It also helped to discover the first exoplanets! Another interesting tidbit is that Arecibo was used to transmit a binary radio message directed at M13, in an attempt to communicate with aliens.
Another exciting thing about Arecibo is the opportunity for undergrad students to participate in research at the observatory during the summer. http://www.naic.edu/reu_program.html Students spend 10 weeks during the summer months working with astronomers, and even get to conduct their own independent observational experiments. Of course, spending a summer in Puerto Rico is also nice.
they shouldn't have sent a poet
http://abstrusegoose.com/446
Having a poet is great to make science more interesting to the masses, but you just can't rely on their, well, anything else.
M95!
http://blogs.discovermagazine.com/badastronomy/2012/03/19/breaking-possible-supernova-in-nearby-spiral-m95
I was watching Cosmos the other day. In the episode, Carl Sagan talked about Kepler and Brahe. Aside from both their respective genius, they had another thing in common: the luck of witnessing supernovae. It was discussed briefly in class about how we were due for one, then BAM! M95!
In 1572 when Brahe observed a supernova, it was still held that the universe beyond the Moon was unchanging. For a new "star" to appear was inconceivable. Surely this new bright spot in the sky would have to be between the Earth and the Moon. However, Brahe noticed that there was no daily parallax of this new object. This meant that it was not only farther away than the Moon, but it was not even within our solar system. Indeed, the SN 1572 as it was later to be named, was 7500 light years away from Earth.
In 1604, a mere 32 years after SN 1572, Kepler saw a supernova of his own (so unfair!). Like Brahe, he too noticed a lack of parallax, furthering the notion of the heavens as being able to change. Both SN 1572 and SN 1604 occurred within our galaxy, and were able to be seen with the naked eye, with magnitudes of -4 and -2.5 respectively (this would mean SN 1572 was almost four times as bright!)
Unfortunately M95 is not within our galaxy (it's about 30 million light years away) and will likely never be visible with the naked eye. Right now M95 has a magnitude of about 13, and our eyes can only detect down to a magnitude of 6. The good news is, you won't need a fancy telescope to see it. Just about any home telescope will work, just point it at Mars and it'll be within half a degree. Happy viewing!
I was watching Cosmos the other day. In the episode, Carl Sagan talked about Kepler and Brahe. Aside from both their respective genius, they had another thing in common: the luck of witnessing supernovae. It was discussed briefly in class about how we were due for one, then BAM! M95!
In 1572 when Brahe observed a supernova, it was still held that the universe beyond the Moon was unchanging. For a new "star" to appear was inconceivable. Surely this new bright spot in the sky would have to be between the Earth and the Moon. However, Brahe noticed that there was no daily parallax of this new object. This meant that it was not only farther away than the Moon, but it was not even within our solar system. Indeed, the SN 1572 as it was later to be named, was 7500 light years away from Earth.
In 1604, a mere 32 years after SN 1572, Kepler saw a supernova of his own (so unfair!). Like Brahe, he too noticed a lack of parallax, furthering the notion of the heavens as being able to change. Both SN 1572 and SN 1604 occurred within our galaxy, and were able to be seen with the naked eye, with magnitudes of -4 and -2.5 respectively (this would mean SN 1572 was almost four times as bright!)
Unfortunately M95 is not within our galaxy (it's about 30 million light years away) and will likely never be visible with the naked eye. Right now M95 has a magnitude of about 13, and our eyes can only detect down to a magnitude of 6. The good news is, you won't need a fancy telescope to see it. Just about any home telescope will work, just point it at Mars and it'll be within half a degree. Happy viewing!
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