Is there any place in the night sky which stimulates our imaginations more than the famous Horsehead? This area of dark dust painted over the smokey veil of emission nebula is one of the most often photographed and visually sought-after regions in Orion. How many of us have used (or bought) a special filter just to see it with your own eyes? Then behold it once again in all of its glory – and all of its mysteries…
“I am happy to present my first image of 2011 with an object that has been long on my target list.” says astrophotographer, Ken Crawford. “This is the famous Horsehead Nebula which is formed by a dark cloud of dust and gas that forms a silhouette against the glow of IC434 behind it. There has been a lot of research done in this region because of the star forming fronts and surrounding molecular clouds with condensing areas that show up as small red clumps. These clumps are glowing red because of the rising temperatures inside are getting hot enough to be seen through the gas surrounding it as they become new stars. These condensing, glowing clumps are called Herbig-Haro objects and can be seen below the Horsehead on the left side and in the cropped image. There is a young new star in the top of the “head” area that sits in a small nebula and has the name B33-1.”
But radiation from this hot star is eroding the stellar nursery. When E.E. Barnard discovered it in 1913, he noted that the edges were “sharp” and “well defined”. Not any more. In just about a century the UV radiation of this O9 star is beginning to show its slow destruction of the cloud…. and that’s not all that is eating away at the familiar equine shape. “We find evidence for a lozenge-shaped clump in the ‘throat’ of the horse, which is not seen in emission at shorter wavelengths. We label this source B33-SMM2 and find that it is brighter at submillimetre wavelengths than B33-SMM1.” says D. Ward-Thompson, et al. “We calculate the stability of this core against collapse and find that it is in approximate gravitational virial equilibrium. This is consistent with it being a pre-existing core in B33, possibly pre-stellar in nature, but that it may also eventually undergo collapse under the effects of the HII region.”
However, destruction is not all this beautiful image reveals. “The bright nebula in the lower left is called NGC2023 and is called a reflection nebula because the blue wavelengths of light are reflected by the dust and gas around the hot blue star.” says Crawford. “There are also Herbig-Haro objects in this active region of star formation. This reflection nebula provides a beautiful contrast of textures and colors that help make the Horsehead nebula one of my all time favorites.”
It’s time once again for another Where In The Universe Challenge. Name where in the Universe this image was taken and give yourself extra points if you can name the telescope or spacecraft responsible for the image. Post your guesses in the comments section, and check back on later at this same post to find the answer. To make this challenge fun for everyone, please don’t include links or extensive explanations with your answer. Good luck!
UPDATE: The answer is now posted below:
As many of you surmised, this is a MESSENGER image of the double-ring basin Rachmaninoff on Mercury. This and other MESSENGER images are showing evidence that the interior smooth plains seen on the planet are products of relatively young volcanism, the youngest documented on Mercury to date. Find out more on this image at the MESSENGER website.
A time-series of black and white and false-color sub-images, from left to right at three sites in a field of transverse dunes at 84.7°N, 0.7°E shows that extensive erosion has taken place in one Mars year. Image courtesy of Science/AAAS.
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Mars, it is a-changin’, and more than scientists expected. Several series of before-and-after images taken by the HiRISE camera on the Mars Reconnaissance Orbiter the past two years show sand dunes in Mars northern hemisphere changing – both gradually and suddenly. A team of researchers analyzing the images say that the changes have been caused mostly by sand and ice cascading down the slipfaces of the dunes. But, also, there could be “alien” processes that we don’t see occurring on Earth.
“The numbers and magnitude of the changes have been really surprising,” said HiRISE Deputy Principal Investigator Candice Hansen.
The white arrows point to a location on the brink of this dune at 84°N, 233°E that had no alcove in the first year of HiRISE operation (MY29) and experienced sublimation activity (middle), which resulted in the new alcove and fan (with total length of 120 m) in MY30. The layer of new material forming the apron is very thin; the original ripples have not been completely buried. Image courtesy Science/AAAS.
In the past, Mars was thought to be a dead world, frozen in time with not many changes taking place on its surface. But since the arrival of high-resolution cameras orbiting the Red Planet – first on the Mars Global Surveyor, and now on MRO and ESA’s Mars Express – that notion has fallen by the wayside. Avalanches, new gullies and now shifting sand dunes are appearing regularly on images from Mars.
Even with the known winds on Mars, scientists had considered the dunes to be fairly static, shaped long ago when winds on the planet’s surface were thought to be much stronger than they are today.
Hansen and her colleagues’ new paper that is published in this week’s edition of the journal Science identifies the seasonal changes from a layer of frozen carbon dioxide – a.k.a or dry ice – which covers the region in winter and sublimates away in the spring, along with stronger-than-expected gusts of wind as initiating sand transport on the northern dunes of Mars.
Three images of the same location taken at different times show seasonal activity causing sand avalanches and ripple changes on a Martian dune. Credit: NASA/JPL/The University of Arizona.
“This gas flow destabilizes the sand on Mars’ sand dunes, causing sand avalanches and creating new alcoves, gullies and sand aprons on Martian dunes,” Hansen said. “The level of erosion in just one Mars year was really astonishing. In some places hundreds of cubic yards of sand have avalanched down the face of the dunes.”
Recently, scientists have seen how the scars of past sand avalanches could be partially erased in just one Mars year. Models of Mars’ atmosphere do not predict wind speeds adequate to lift sand grains, and data from Mars landers such as Phoenix show high winds are a rare occurrence.
“Perhaps polar weather is more conducive to high wind speeds,” Hansen said.
The dune margin in MY29 image PSP_008968_2650 at 84.7°N, 0.7°E is compared with MY30 ESP_017895_2650. Image courtesy of Science/AAAS
The researchers say changes were seen in about 40 percent of far-northern monitoring locations over the two-Mars-year period of the study.
Related research with HiRISE previously identified gully-cutting activity in smaller fields of sand dunes covered by seasonal carbon-dioxide ice in Mars’ southern hemisphere. A report four months ago showed that those changes coincided with the time of year when ice builds up.
A false-color image of dark sand dunes at high northern latitudes on Mars that are covered seasonally by a layer of condensed carbon dioxide (dry ice), shown in this image. When the sun rises in the spring the ice begins to sublimate. Gas flow from the bottom of the ice layer propels sand from the dunes out through cracks to the top of the ice and down the dune slipface. Image courtesy of NASA/JPL/University of Arizona
“The role of the carbon-dioxide ice is getting clearer,” said Serina Diniega of NASA’s Jet Propulsion Laboratory, Pasadena, Calif., lead author of the earlier report and a co-author of the new report. “In the south, we saw before-and-after changes and connected the timing with the carbon-dioxide ice. In the north, we’re seeing more of the process of the seasonal changes and adding more evidence linking gully activity with the carbon dioxide.”
“Understanding how Mars is changing today is a key first step to understanding basic planetary processes and how Mars changes over time,” said HiRISE Principal Investigator Alfred McEwen, a co-author of both reports. “There’s lots of current activity in areas covered by seasonal carbon-dioxide frost, a process we don’t see on Earth. It’s important to understand the current effects of this unfamiliar process so we don’t falsely associate them with different conditions in the past.”
Mars500 crew just seconds before ingressing their module for a 520 day stay in June 2010. Credit: ESA
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Six men from Europe, Russia and China on a 520-day mock mission to Mars, have now reached the point in their mission where they have arrived ‘in orbit’ of Mars. Mars500, the first full-duration simulation, is like a real Mars mission, where the crew has been in isolation, living and working like astronauts, eating special food and exercising the same way as crews aboard the International Space Station, and even experiencing lag time in communications. Now after 244 days of virtual interplanetary flight, the crew is getting ready to ‘land’ on Mars on February 12 where they will make three EVAs onto simulated Martian terrain.
Mars500 is not a just a flight of fancy or fantasy, but scientists from Russia and the European Space agency say it is a “pioneering international study of the complex psychological and technical issues that must be tackled for long spaceflights.”
Mars500 crew just seconds before ingressing their module for a 520 day stay in June 2010. Credit: ESA
The simulation has been running for more than eight months in hermetically sealed modules imitating a Mars spacecraft at the Institute of Biomedical Problems (IBMP) in Moscow.
“Mars500 is a visionary experiment,” said Simonetta Di Pippo, ESA Director for Human Spaceflight. “Europe is getting ready to make a step further in space exploration: our technology and our science grow stronger every day. Mars 500 today is only an enriching simulation, but we are working to make it real.”
The Mars500 facility has no windows, but a laptop running Celestia, a freeware space simulation software, acts as a virtual window as the crew approached the Red Planet. Credits: ESA
The crew has now opened a hatch between the mothership and the mockup of a lander that, according to script, was launched separately to Mars.
In the coming days, the cargo inside the ‘lander’ will be transferred into the habitat and the lander will be prepared for ‘undocking’ and ‘landing’.
The crew will then divide: Russian Alexandr Smoleevskiy, Italian Diego Urbina and Chinese Wang Yue will enter the lander, while the rest of the crew, Romain Charles from France and Sukhrob Kamolov and Alexey Sitev from Russia ‘remain in orbit’.
The hatch between the interplanetary spacecraft and lander will be closed on 8 February. The lander will undock and ‘touch down’ on Mars on 12 February.
The Mars terrain simulator of the Mars500 facility. The crew will drive a rover and place sensors during their sorties. Credits: IBMP/ Oleg Voloshin
The simulated Martian terrain is actually housed in a large hall alongside the Mars500 modules. The first EVA will take place on February 14, with subsequent sorties taking place on February 18 and 22.
Then the lander will return to orbit and dock with the mothership the following day.
The lander crew will stay in quarantine for three days before the hatch is opened on 27 February and the astronauts are reunited.
Mars500 participant Diego Urbina with a computer simulation in the Mars500 facility. Credits: ESA
After that, the crew is faced with another long, monotonous ‘interplanetary cruise’ before arriving home in early November 2011.
Keplers 1200 Planet candidates by size. Finding exoplanets is getting easier, LUVOIR will helps us find signs of life, if any, on them. Credit: NASA/Wendy Stenzel
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With the startling new finding of dozens of Earth-sized extrasolar planets, NASA’s Kepler planet hunting space telescope has just revolutionized our understanding of Earths place in the Universe and the search for Extraterrestrial Life. And the historic science discovery is based on data collected in just the first few months of operation of the powerful telescope as it scans only a tiny portion of the sky.
The discovery of 1235 new extrasolar planet candidates was announced today (Feb.2) by NASA and Kepler scientists at a media briefing. 68 of these planet candidates are Earth-sized. Another 288 are Super-Earth-size, 662 are Neptune-size and 165 are Jupiter-size. Most of these candidates orbit stars like our sun.
Even more significant is that 54 of the planet candidates are located within the ‘habitable zone’ of their host stars and 5 of those are Earth-sized. Before today we knew of exactly ZERO Earth-sized planets within the habitable zone. Now there are 5.
Finding a ‘Pale Blue Dot’ or ‘Second Earth’ inside a habitable zone that harbors water and environmental conditions that can support life is the ‘Holy Grail’ of science.
Are We Alone ?
“We went from zero to 68 Earth-sized planet candidates and zero to 54 candidates in the habitable zone – a region where liquid water could exist on a planet’s surface. Some candidates could even have moons with liquid water,” said William Borucki of NASA’s Ames Research Center, Moffett Field, Calif.. Borucki is the science principal investigator for NASA’s Kepler mission.
“Five of the planetary candidates are both near Earth-size and orbit in the habitable zone of their parent stars.”
Earth-sized water worlds are the most conducive to the formation and evolution of alien life forms. Water is an essential prerequisite for life as we know it.
“Kepler’s blown the lid off everything we know about extrasolar planets,” said Debra Fischer, professor of Astronomy at Yale University, New Haven, Conn
Kepler's over 1200 planet candidates as of Feb. 1, 2011. Credit: NASA/Wendy Stenzel
Kepler is the first NASA mission capable of finding Earth-size planets in or near the habitable zones around their parent stars. The mission uses the transit method to detect the tell tale signatures of planets. The goal is to determine how common are planets the size of Earth orbiting inside the habitable zone of stars like our sun.
Kepler measures the miniscule decreases in the brightness of stars caused by planets crossing in front of them and blocking the starlight. Imagine calculating the difference in light transmission caused by a flea sitting on a cars headlight.
Follow up observations over a period of several years will be required to confirm these results, the scientists explained. Astronomers expect that over 80% of the candidate planets will be positively confirmed as real planets by utilizing ground based observatories and the Spitzer Space Telescope.
For an Earth-sized planet orbiting a sun-like star inside the habitable zone, transits occur about once per year. Since three transits are required to verify a planets status, it will therefore take about three years to reach a definitive conclusion.
These remarkable new planet discoveries are based on observations from only the first four months of Kepler’s telescopic operations – May 12, 2009 to Sept. 17, 2009. The space based observatory continuously monitors more than 156,000 stars using 42 CCD detectors with a field of view that covers only 1/400 of the sky.
“Kepler is making good progress towards its goals,” said Borucki
“We have found over twelve hundred candidate planets – that’s more than all the people have found so far in history.”
“Imagine if we could look wider. Kepler looks at one 400th of the sky. If we had 400 of these fields of view, we’d see 400 times that number of candidates. We would see 400,000 candidate planets.”
Keplers over 1200 Planet candidates sorted by size
“The fact that we’ve found so many planet candidates in such a tiny fraction of the sky suggests there are countless planets orbiting stars like our sun in our galaxy,” Borucki amplified. “Our results indicate there must be millions of planets orbiting the stars that surround our sun.”
“If we find that Earth’s are common in the habitable zones of stars, very likely that means life is common around these stars.”
“Kepler has shown that planetary systems like our own are common,” said Debra Fischer.
Planets in Keplers Field of View.
Before and after the discovery of over 1200 planet candidates by NASA’s Kepler Space Telescope.
“The search for planets is motivated by the search for life,” Fischer added.
“We have allowed the public to participate though the website Planethunters.org,” she added. “And now we have over 16,000 dedicated users. The public is excited to be a part of research and history.”
“Thanks to Kepler for this treasure chest of data!” Fisher concluded.
Kepler is just the first step in finding Earth sized and Earth like planets. “We are building the foundation for future generations of explorers,” said Borucki.
“Future missions will be developed to study the composition of planetary atmospheres to determine if they are compatible with the presence of life. The design for these missions depends on Kepler finding whether Earth-size planets in the habitable zone are common or rare.”
The first planets beyond our solar system were discovered in 1995. Up to today there were just over 500 known extrasolar planets.
Kepler now has 15 confirmed extrasolar planet discoveries and over 1200 possible candidates.
NASA’s Kepler spacecraft was launched on March 6, 2009 from Launch Complex 17-B atop a Delta II rocket at Cape Canaveral Air Force Station in Florida. See spacecraft and launch photos below
Kepler’s science operations are currently funded for three and one half years of operations until November 2012. The mission’s lifetime – and its goal of discovering multitudes of new planets as small as Earth – can be extended if NASA funding is approved by Congress and the President.
William Borucki – Explains Keplers Discovery of Earth Sized Planets
Science principal investigator for NASA’s Kepler mission, NASA’s Ames Research Center
Video Caption: NASA’s Kepler mission has discovered its first Earth-size planet candidates and its first candidates in the habitable zone, a region where liquid water could exist on a planet’s surface. Five of the potential planets are near Earth-size and orbit in the habitable zone of smaller, cooler stars than our sun.
Kepler also found six confirmed planets orbiting a sun-like star, Kepler-11. This is the largest group of transiting planets orbiting a single star yet discovered outside our solar system. Located approximately 2,000 light years from Earth, Kepler-11 is the most tightly packed planetary system yet discovered. All six of its confirmed planets have orbits smaller than Venus, and five of the six have orbits smaller than Mercury’s.
What is an Earth like planet ? Explantion here
David Charbonneau, an exoplanet researcher at Harvard University, explains what scientists mean when they say “earthlike planet” and “super Earth.” This interview was recorded at NASA’s Goddard Space Flight Center on December 10, 2010, by NASA science writer Daniel Pendick.
Kepler Mission Star Field
An image by Carter Roberts of the Eastbay Astronomical Society in Oakland, CA, showing the Milky Way region of the sky where the Kepler spacecraft/photometer will be pointing. Each rectangle indicates the specific region of the sky covered by each CCD element of the Kepler photometer. There are a total of 42 CCD elements in pairs, each pair comprising a square.
Credit: Carter Roberts / Eastbay Astronomical Society.Kepler's target region in the Milky Way. Credit: Jon LombergKepler being prepared in the clean room at Astrotech
prior to launch on March 6, 2009. Credit: nasatech.net
More Kepler photos courtesy of nasatech.net here
Delta 2 rocket streaks to the heavens.
Launch of NASA’s Kepler planet hunting space telescope from Cape Canaveral Air Force Station, FL, Complex 17, on March 6, 2009 at 10:49 p.m. Credit: Ben CooperBen Cooper Featured on Astronomy Picture of the Day (APOD); March 9, 2009
Launch Pad 17 B and a Delta II rocket
from my perch on the 8th floor of Launch Pad 17 A as rocket is encased in launch tower. Credit: Ken KremerView of Launch Complex 17 B and cryogenic storage tanks by Ken Kremer
Space Florida and Bigelow Aerospace signed a Memorandum of Understanding to open an exhibit center on Florida's Space Coast. Photo Credit: Jason Rhian
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CAPE CANAVERAL – Another NewSpace firm was in the Cape Canaveral area to ink a deal with Florida’s aerospace organization, Space Florida, today. A meeting was held today at the Radisson Resort at the Port to discuss the partnership of Space Florida and Bigelow Aerospace to establish a exhibit center on the Space Coast. Numerous dignitaries and officials in the space industry attended as did elected officials such as Rep. Bill Posey. The brief session started at 1 p.m. EDT and lasted about an hour.
“My purpose by coming here today is to provide a message of hope, that this country is absolutely capable of taking charge of the future of space, not just bequeathing it to other countries and other nations,” said Robert Bigelow founder and president of Bigelow Aerospace at the end of Wednesday’s meeting. “The private sector in this country has the ambition and the chutzpah to go ahead and take this on…”
Space Florida and the commercial space firm inked a deal to build an exhibit center that will showcase one-third scale replicas of Bigelow Aerospace’s inflatable space stations. Two prototypes of which have already been sent into orbit via Russian rockets. The exhibit will primarily be utilized for marketing purposes.
The event was closed with a signing of the Memorandum of Understanding and a brief question and answer session with those in attendance and the media.
Frank DiBello president of Space Florida shakes hans with Robert Bigelow, the founder and president of Bigelow Aerospace. Photo Credit: Jason Rhian
This new effort does however highlight the growing interest of the emerging commercial aerospace market in Florida’s established space infrastructure. Bigelow stated that it was possible that Florida could be the place where much of his firm’s hardware is launched from. However, he mentioned other U.S. launch facilities as well. Approximately 25 flights will be required to make Bigelow’s space station objectives a reality.
“If you think about the process of a country or a major corporation wanting to fly something into space to conduct research, it’s not a simple device that they fly, it is a research program that they find that fits into a multi-year plan,” said Frank DiBello the president of Space Florida. “It is a multi-year project for every one of these customers, we see this as an industry that we are growing – and this is a brick that were placing into the wall of that industry.”
If Florida is selected this could well bring something very valuable back to the Space Coast region of Florida – jobs. These efforts could bring about 1,800 jobs to the area.
Robert Bigelow, president of Bigelow Aerospace discusses his plans for the future. Photo Credit: Jason Rhian
Space Florida is the arm of the State of Florida that is responsible for economic development of aerospace business. The organization was established by the Florida legislature back in 2006 from three separate entities, the Florida Aerospace Finance Corporation, the Florida Space Authority and the Florida Space Research Institute.
Bigelow Aerospace was founded in 1999 and it has since flown two prototypes into space Genesis I and Genesis II which were launched atop a Dnepr ICBM from the Dombarovskiy Cosmodrome in Russia. At the meeting in Cape Canaveral on Wednesday Bigelow stated that one of the main customers that his company is looking at is smaller nations that cannot afford their own space program and would like to send payloads into orbit.
Replicas of two of Bigelow Aerospace's spacecraft. The ones on display at the exhibit center will be one-third the size of the actual flight models. Photo Credit: Jason Rhian
In the constellation of Ophiuchus, above the disk of our Milky Way Galaxy, there lurks a stellar corpse spinning 30 times per second — an exotic star known as a radio pulsar. This object was unknown until it was discovered last week by three high school students. These students are part of the Pulsar Search Collaboratory (PSC) project, run by the National Radio Astronomy Observatory (NRAO) in Green Bank, WV, and West Virginia University (WVU).
The pulsar, which may be a rare kind of neutron star called a recycled pulsar, was discovered independently by Virginia students Alexander Snider and Casey Thompson, on January 20, and a day later by Kentucky student Hannah Mabry. “Every day, I told myself, ‘I have to find a pulsar. I better find a pulsar before this class ends,'” said Mabry.
When she actually made the discovery, she could barely contain her excitement. “I started screaming and jumping up and down.”
Thompson was similarly expressive. “After three years of searching, I hadn’t found a single thing,” he said, “but when I did, I threw my hands up in the air and said, ‘Yes!’.”
Snider said, “It actually feels really neat to be the first person to ever see something like that. It’s an uplifting feeling.”
As part of the PSC, the students analyze real data from NRAO’s Robert C. Byrd Green Bank Telescope (GBT) to find pulsars. The students’ teachers — Debra Edwards of Sherando High School, Leah Lorton of James River High School, and Jennifer Carter of Rowan County Senior High School — all introduced the PSC in their classes, and interested students formed teams to continue the work.
Even before the discovery, Mabry simply enjoyed the search. “It just feels like you’re actually doing something,” she said. “It’s a good feeling.”
Basics of a Pulsar CREDIT: Bill Saxton, NRAO/AUI/NSF
Once the pulsar candidate was reported to NRAO, Project Director Rachel Rosen took a look and agreed with the young scientists. A followup observing session was scheduled on the GBT. Snider and Mabry traveled to West Virginia to assist in the follow-up observations, and Thompson joined online.
“Observing with the students is very exciting. It gives the students a chance to learn about radio telescopes and pulsar observing in a very hands-on way, and it is extra fun when we find a pulsar,” said Rosen.
Snider, on the other hand, said, “I got very, very nervous. I expected when I went there that I would just be watching other people do things, and then I actually go to sit down at the controls. I definitely didn’t want to mess something up.”
Everything went well, and the observations confirmed that the students had found an exotic pulsar. “I learned more in the two hours in the control room than I would have in school the whole day,” Mabry said.
Pulsars are spinning neutron stars that sling lighthouse beams of radio waves or light around as they spin. A neutron star is what is left after a massive star explodes at the end of its normal life. With no nuclear fuel left to produce energy to offset the stellar remnant’s weight, its material is compressed to extreme densities. The pressure squeezes together most of its protons and electrons to form neutrons; hence, the name neutron star. One tablespoon of material from a pulsar would weigh 10 million tons — as much as a supertanker.
The object that the students discovered is in a special class of pulsar that spins very fast – in this case, about 30 times per second, comparable to the speed of a kitchen blender.
“The big question we need to answer first is whether this is a young pulsar or a recycled pulsar,” said Maura McLaughlin, an astronomer at WVU. “A pulsar spinning that fast is very interesting as it could be newly born or it could be a very old, recycled pulsar.”
A recycled pulsar is one that was once in a binary system. Material from the companion star is deposited onto the pulsar, causing it to speed up, or be recycled. Mystery remains, however, about whether this pulsar has ever had a companion star.
If it did, “it may be that this pulsar had a massive companion that exploded in a supernova, disrupting its orbit,” McLaughlin said. Astronomers and students will work together in the coming months to find answers to these questions.
The PSC is a joint project of the National Radio Astronomy Observatory and West Virginia University, funded by a grant from the National Science Foundation. The PSC, led by NRAO Education Officer Sue Ann Heatherly and Project Director Rachel Rosen, includes training for teachers and student leaders, and provides parcels of data from the GBT to student teams. The project involves teachers and students in helping astronomers analyze data from the GBT, a giant, 17-million-pound telescope.
Some 300 hours of observing data were reserved for analysis by student teams. Thompson, Snider, and Mabry have been working with about 170 other students across the country. The responsibility for the work, and for the discoveries, is theirs. They are trained by astronomers and by their teachers to distinguish between pulsars and noise. The students’ collective judgment sifts the pulsars from the noise.
All three students had analyzed thousands of data plots before coming upon this one. Casey Thompson, who has been with the PSC for three years, has analyzed more than 30,000 plots.
“Sometimes I just stop and think about the fact that I’m looking at data from space,” Thompson said. “It’s really special to me.”
In addition to this discovery, two other astronomical objects have been discovered by students. In 2009, Shay Bloxton of Summersville, WV, discovered a pulsar that spins once every four seconds, and Lucas Bolyard of Clarksburg, WV, discovered a rapidly rotating radio transient, which astronomers believe is a pulsar that emits radio waves in bursts.
Those involved in the PSC hope that being a part of astronomy will give students an appreciation for science. Maybe the project will even produce some of the next generation of astronomers. Snider, surely, has been inspired.
“The PSC changed my career path,” confessed Thompson. “I’m going to study astrophysics.”
Snider is pleased with the idea of contributing to scientific knowledge. “I hope that astronomers at Green Bank and around the world can learn something from the discovery,” he said.
Mabry is simply awed. “We’ve actually been able to experience something,” she said.
The PSC will continue through 2011. Teachers interested in participating in the program can learn more at this link.
Using data from the Kepler space telescope, scientists have discovered a horde of six planets orbiting a sun-like star, approximately 2,000 light years from Earth. This is the largest group of planets detected so far around another star. The planets in this newly found solar system are relatively small – they range from 2.3 to 13.5 times the mass of the Earth – and are amazing mix of rock and gases. All six planets are crowded within an orbit the size of Venus’ orbit around our Sun; however, the inner five are closer to their star than any planet in our solar system.
“This is a surprisingly flat and compact system of six transiting planets,” said Jack Lissauer, co-investigator on the Kepler mission, speaking at a press conference on February 2, 2011. “The five inner planets are especially close together, something we didn’t think would happen for worlds of this size. This discovery forces us to go back and look at formation models of planets.”
Lissauer added that the close proximity of the six worlds around the star — now called Kepler 11 — also means that the planets are perturbing each others’ orbits. While having a multi-planet system makes it difficult to untangle the signals from each planet, it has the added benefit of providing more information about each of the worlds.
“In a system where the planets are tugging on one another, that means we can weigh the planets,” Lissauer said. “We have found they are low density planets; some are fluffy, sort of like marshmallows. But they are not all gas, so maybe like a marshmallow with a little hard candy at the core.”
Lissauer was incredibly enthusiastic about the discovery.
“We really were just amazed at his gift that nature has given us,” he said. “With six transiting planets, and five so close and getting the sizes and masses of five of these worlds, there is only one word that adequately describes the new finding: Supercalifragilisticexpialidocious.”
Kepler finds planets by using the transit method. The planets’ orbits are edge-on as seen from Earth, so when they pass in front of their star they block a small portion of its light. That dip in brightness is what Kepler detects.
Lissauer explained the animation (seen at the top of this article): “This is the view of Kepler, and it looks like a very special clock, one with six hands moving at six different rates, and we interpret this as six planets orbiting near the same plane. Then, you can see how it might look face on. This is the most compact system of planets every discovered by any technique anywhere.”
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The time between transits provides the orbital period. To determine the planets’ masses, the scinetists analyzed slight variations in the orbital periods caused by gravitational interactions among the planets.
Lissauer said the five close inner bodies tug on one another’s orbit, and sometimes the pull can retard the transit time by 10-20 minutes.
“The timing of the transits is not perfectly periodic, and that is the signature of the planets gravitationally interacting,” said Daniel Fabrycky, a Hubble postdoctoral fellow at UC Santa Cruz, who led the orbital dynamics analysis. “By developing a model of the orbital dynamics, we worked out the masses of the planets and verified that the system can be stable on long time scales of millions of years.”
Five of the planets’ orbital periods are all less than 50 days, and the sixth planet is larger and farther out, with an orbital period of 118 days and an undetermined mass.
Kepler-11 is a sun-like star around which six planets orbit. At times, two or more planets pass in front of the star at once, as shown in this artist's conception of a simultaneous transit of three planets observed by NASA's Kepler spacecraft on Aug. 26, 2010. Image credit: NASA/Tim Pyle
Finding a large multiplanet system has many people wondering when Kepler will discover an Earth-like world. The scientists on the panel today estimated it will take three years of Kepler data to find another Earth.
“No one is more eager to get to the point of an Earth-like planet than the Kepler team,” said Douglas Hudgins, Kepler program scientist. That will require at least 3 years of Kepler data and painstaking follow-up observations from ground-based before those types of discoveries will emerge from the data.”
Hudgins reminded everyone that the first 15 years of exoplanet searches from ground-based observing produced about 500 planets, and that last year the Kepler team announced 750 exoplanet candidates from just the first three months of Kepler observations. With the release of more Kepler data today, there are now more than 1,200 planet candidates.
“The key thing to remember about every planet candidate,”Hudgins said, “ is that every time we see in data evidence of a signal, there is required analysis and follow-up data and observations to determine it is actually planet and not something masquerading as a planet.”
Translation: this takes time and won’t happen overnight.
But with the release of more data, the Kepler team said they wants to harness the horsepower of the whole planetary community, as well as citizen scientists to scour through the data. The Planet Hunters program from Galaxy Zoo has been a successful project that allows anyone to contribute the science of finding extrasolar planets.
The public has made over 1.3 million classification using just the first 30 days of publicly released Kepler data,” said Debra Fischer, professor of Astronomy at Yale University who heads up the Planet Hunters project. “We are really excited and appreciative that NASA and the Kepler mission has essentially quadrupled the amount of public data with the early release of their latest data.”
Mars is a small planet. In fact, for scientists who do solar system modeling, the planet is too small. “This is an outstanding problem in terrestrial planet formation,” said Dr. David Minton from the Southwest Research Institute. “Everyone who does simulations of how you form terrestrial planets always ends up with a Mars that is 5-10 times bigger than it is in real life.” Minton has been working alongside colleague Dr. Hal Levison to create new simulations that explain the small size of Mars by including the effect of what is known as planetesimal-driven migration, and additionally, small objects that Minton calls “Marstinis” could stir or shake up our ideas about the early solar system and the Late Heavy Bombardment.
Planetary scientists agree that the terrestrial planets formed very quickly within the first 50-100 million years of the solar system’s history and our Moon formed from an impact between a Mars-sized object and the proto-Earth at some point during that time. Much later was the Late Heavy Bombardment, the time period where a large number of impact craters formed on the Moon within a time span of only seventy million years — and by inference Earth, Mercury, Venus, and Mars were likely pummeled as well.
Most planetary formation theories can’t account for this intense period of bombardment so late in the solar system’s history, but Levison was part of a team that in 2005 proposed the Nice Model, which suggested how the Late Heavy Bombardment was triggered when the giant planets — which formed in a more compact configuration – rapidly migrated away from each other (and their orbital separations all increased), and a disk of small “planetesimals” that lay outside the orbits of the planets was destabilized, causing a sudden massive delivery of these planetesimals – asteroids and comets — to the inner solar system.
But, according to the model, planetesimals likely also caused the migration of the planets, too. The planets formed from a giant disk of gas, dust, rocky debris and ice surrounding the early Sun. Debris coalesced to form bigger planet-sized objects, and simulations shows that bigger planet-sized object embedded in a disk of smaller objects will migrate as a result of angular momentum and energy conservation as the planets scatter the planetesimals they encounter.
Artists concept of planetesimals and Jupiter.
“Perturbations from small rocky or icy objects surrounding a larger object can cause the larger object to ‘scoot’ along the disk,” Minton told Universe Today. “Every time these little planetesimals encounter the bigger object, they actually cause a little nudge in the position of the bigger object. It turns out if you work out the math, if there is any sort of slight imbalance to the number of objects encountering on the sunward side versus encountering on the anti-sunward side, you can actually cause a net movement of the big body, and it actually happens pretty quickly.”
Minton and Levison have been applying the same physics of planetesimal-driven migration to the formation of the terrestrial planets.
“In the case of Mars, imagine these planetary embryos located in the Earth-Venus zone,” Minton said. “Then you have a one little embryo growing to become Mars-sized, and it would start migrating because of planetesimal-driven migration, and it scoots away from the other guys. So it has left the pack, and as it moves through the disk, it gets stranded away from where all the action is going on.”
So Mars’ growth got stalled at its current size because it migrated away from the planet-building materials.
Minton said their simulations of this work really well.
“We’ve been doing a lot of math and the migration is pretty rapid,” he said, “and Mars could migrate through the disk before any other Mars-sized planet could form. In an early solar system where you have a Mars stranded off at the edge of the disk at 1.5 AU, which is where it is right now and all the other action going on in the Earth-Venus zone, then Earth and Venus were able to grow to the size they are now, where they are both roughly the same size and mass and Mars is stranded on its own.”
And with Mars there is a twist of Marstinis, which could offer an alternate explanation for the Late Heavy Bombardment.
The migrating Mars could have picked up planetesimals in its resonance, where two or more orbiting bodies exert a gravitational influence on each other.
“It is not at all obvious why that is,” Minton said, “but the same thing is thought to have happened in the outer solar system which is what gave Pluto its orbit. We think Pluto was actually picked up in the 3:2 resonance with Neptune when Neptune migrated out, and that’s why Pluto and the other “Plutinos” are living in these resonances with Neptune.”
The Plutinos are other Kuiper Belt objects near Pluto. That resonance means Pluto and the Plutinos go around the Sun three times for every 2 times Neptune does. There are also Two-tinos, which are caught in a 1:2 resonance with Neptune – and which are found towards the outer edge of the Kuiper belt. The new simulations show that these lines of resonances are almost like a snowplow, and as Neptune migrated out it picked up all these little icy bodies, Pluto and the Plutinos.
A graphic of the solar system in its current configuration; Mars is small. Credit: NASA
This also could have happened to Mars, and as Mars migrated through the disk it would have also picked up little objects.
“I’ve decided to calls these Marstinis, to keep in the Plutino and Two-tino, theme,” Minton said with a grin. “I don’t know if that will stick or not.”
But the interesting thing about the Marstinis, Minton said, is that a 3:2 resonance with Mars is actually a very unstable zone.
“There is actually a resonance there with Saturn that only existed in the time of the Late Heavy Bombardment,” he said, “so before that, Saturn — we think — was in a different position, so this particular resonance was in a different position. So it was only after the giant planets migrated to their current location that this resonance location became unstable. So we think that these Marstinis would have been stable and in that interim period between the end of planet formation and the Late Heavy Bombardment, all of a sudden this region became unstable when the planets shifted positions to their current locations.”
So could the Marstinis be responsible for the Late Heavy Bombardment?
“These Marstinis were pushed out from the planet forming regions out to the asteroid belt,” Minton said, “then all of a sudden the planets migrated and this whole region became unstable and so they all could have gone flinging into the inner solar system and end up hitting the Moon.”
Questions abound about the Late Heavy Bombardment.
There are a couple of other arguments, too where the Marstinis fit the profile of what hit the Moon during the Late Heavy Bombardment.
“We have reasons to think that the objects that hit the Moon during the Late Heavy Bombardment were sort of like asteroids but not exactly like the asteroids we have now,” Minton said. “So, there are some chemical arguments you can make, also you can make some arguments from the impact probabilities that may not have been enough mass in the asteroid belt to supply all the asteroids and impacts we see on the Moon.”
But there are other outstanding issues such as how long the Late Heavy Bombardment lasted, when it started, were comets ever important in the bombardment history of the Moon or was it all asteroids? Minton said further exploration of the Moon would answer many of these questions.
“These are all things that we really need to go to the Moon to find out and there is almost nowhere else you can go to do it. It really is one of the best places to go to understand all the solar system history.
Minton will present his findings at the upcoming Lunar and Planetary Science Conference in March, 2011.
You can listen to an interview I did with Minton about planetesimal-driven migration for the NASA Lunar Science Institute podcast (also available on the 365 Days of Astronomy.)
A view of the interior of a meteorite from Mars shows a vein through which water has flowed. Credit: University of Leicester
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Scientists say a close-up look inside rare meteorite fragments from Mars shows evidence that impacts created flowing water near the surface of the Red Planet. At look at five different meteorite samples, including what is thought the be one of the very first Martian meteorite ever found on Earth, shows veins resulting from the impact and serpentine mineralization, which is associated with the production of methane.
PhD student Hitesh Changela and Dr. John Bridges from the University of Leicester used electron microscopes to study the structure and composition of five nakhlite meteorites, including one that was found in 1911 in El-Nakhla in Egypt (the meteorites were named after the location in which they were found). The meteorites had been housed in Natural History Museum, London, and the scientists sliced minute slivers of rock from the samples, about 0.1 microns thick.
By comparing the five meteorites, they showed the presence of veins created during an impact on Mars. Changela and Bridges suggest that this impact was associated with a 1-10 km diameter impact crater, and buried ice melted during this impact, creating flowing water which then deposited clay, serpentine minerals, carbonate and a gel deposit in the veins.
The scientists say their findings tie in with the recent water-related geological discoveries of clay and carbonate on the surface of Mars made by NASA and ESA orbiting spacecraft and the Mars Exploration rovers.
Nanometre scale atomic lattice spacings (measured by high resolution TEM) in serpentine. Credit: University of Leicester
“We are now starting to build a realistic model for how water deposited minerals formed on Mars,” said Bridges, “showing that impact heating was an important process. The constraints we are establishing about temperature, pH and duration of the hydrothermal action help us to better understand the evolution of the Mars surface. This directly ties in with the current activities of landing site selection for Mars rovers and Mars Sample Return. With models like this we will better understand the areas where we think that water was once present on Mars.”
Since serpentine mineralization is associated with the production of methane, the scientists say further research on the meteorites could help show how the methane was produced. A mission heading to Mars in 2016, the Trace Gas Orbiter, will help search for and understand the origin of any methane — a potential biomarker — in Mars’ atmosphere.
Findings from the research have been published in Meteoritics and Planetary Science (Dec. 2010 issue, vol 45).
