Artist's impression of an asteroid impact on early Earth (credit: NASA)
Earth, with its blue hue visible from space, is known for its abundant water – predominately locked in oceans – that may have come from an extraterrestrial source. New research indicates that the source of Earth’s water isn’t from ice-rich comets, but instead from water-bearing asteroids.
Looking at the ratio of hydrogen to deuterium, a heavy isotope of hydrogen, in frozen water, scientists can get a pretty good idea of the distance the water formed in the solar system. Comets and asteroids farther from the Sun have a higher deuterium content than ice formed closer to the Sun. Scientists, led by the Carnegie Institution for Science’s Conel Alexander, compared water from comets and from carbonaceous chondrites. What they found challenges current models in how the solar system formed.
Primeval Earth was a hot and dry place. Any water that may have formed with Earth was boiled away from the scorching crust. Ultraviolet light from the newly formed Sun stripped hydrogen atoms from the water molecules leaving no rain to fall back on the surface. Scientists believe that both comets and carbonaceous asteroids formed beyond the orbit of Jupiter, perhaps at the very fringes of the solar system, then moved inward bringing both water and organic material to Earth. If this were true, Alexander and his colleagues suggest that ice found in comets and the remnants of ice preserved in carbonaceous chondrites in the form of clays would have similar isotopic composition.
After studying 85 carbonaceous chondrites, supplied by Johnson Space Center and the Meteorite Working Group, they show in a paper released today by Science Express that they likely did not form in the same regions of the solar system as comets because they have much lower deuterium content. They formed closer to the Sun, perhaps in the asteroid belt between Mars and Jupiter. And its that material that rained on early Earth to create the wet planet we know today.
“Our results provide important new constraints for the origin of volatiles in the inner solar system, including the Earth,” Alexander said. “And they have important implications for the current models of the formation and orbital evolution of the planets and smaller objects in our solar system.”
Image caption: Artist impression of an asteroid impact on early Earth (credit: NASA)
Image caption 2: This is a cross-section of a chondritic meteorite.
Several gorgeous images are in this week’s update from the HiRISE camera on board the Mars Reconnaissance Orbiter. This lovely image shows the cliffs at the edges of huge ice sheet at the North Pole of Mars. These cliffs are about 800 meters (2,600 feet) high, and the ice sheet is several kilometers thick at its center. This is a great spot to look for ice avalanches that HiRISE has captured previously. The HiRISE team said that the slopes of these cliffs are almost vertical, plus dense networks of cracks cover the icy cliff faces making it easier for material to break free. The team regularly monitors sites like this to check for new blocks that have fallen. You can look for yourself to see if any avalanches have occurred since the last image was taken of this area, almost exactly one Martian year ago.
The HiRISE scientists monitor these regions to help in understand the climatic record stored in the ice sheet itself.
What else did HiRISE see this week?
These cool-looking dunes look reminiscent of Pac-Man, and they might even be moving across the surface of Mars! They are approximately 100 meters across and are traversing a bumpy, hard terrain, pushed across the surface by the winds on Mars. The HiRISE team will take more images of this dune field in subsequent passes to determine whether these dunes are really moving.
This image shows a gullied crater in the Southern mid-latitudes with light-toned deposits near the center of its floor, and two areas of collapsed terrain at the northern and southern edges of the crater floor.
For more information on each of these images, click on them to see the original page on the HiRISE website, or go to the HiRISE website to see all the wonderful images from Mars.
After completing 193 days in space as a member of the Expedition 30 and 31 crews, astronaut Don Pettit returned to Earth on July 1, 2012. Don is not your average, ordinary, fighter-pilot astronaut: he’s got a penchant for science, with a unique way of looking at things. He spent his expedition performing crazy zero-gravity experiments, grappling the first commercial spacecraft to visit the ISS, and blogging as his alter-ego, a zuchinni plant, among other things. Universe Today had the chance to talk with Pettit this morning about his experiences:
Nancy: Good morning Don. It’s an honor to talk with you. Congratulations on such a successful expedition.
Don Pettit: It’s great to talk with you!
Nancy: You did a lot of science experiments during your stay in space, both the official ISS program experiments and also your own “Science off the Sphere” experiments. Of the official ones, which was the most interesting and engaging or perhaps what you felt was the most important experiment that you did?
Don Pettit: There were two categories of experiments that really captivated me. One is the human life science experiments that we do on ourselves, where we poke and prod ourselves and take blood and other samples, trying to figure out how this thing called the human being operates in a weightless environment. The other category of experiment that I thought was really fascinating was combustion. That’s a fancy way of saying ‘fire’ which of course is what is required to power our current civilization.
Caption: Pettit working with the Structure and Liftoff In Combustion Experiment (SLICE) in the Destiny laboratory of the International Space Station. Pettit conducted three sets of flame tests, followed by a fan calibration. This test will lead to increased efficiency and reduced pollutant emission for practical combustion devices. Credit: NASA
Nancy: What was your favorite Science off the Sphere experiment that you did?
Don Pettit: Oh, probably the one that has to do with the knitting needles and looking at charged droplets in a stable orbit around the knitting needles. That was really fun and simple and a fun demonstration of what you can do when you remove gravitational forces and replace them with small forces like charged forces.
Nancy: I think that was my favorite one too!
I want to say thank you on behalf of everyone, I think, on planet Earth, for the amazing images you took during your mission– the star trails, the aurorae, the transit of Venus are just a few examples — your images were just spectacular. How important is the photography that the astronauts do as far as documenting your expedition and being able to share your experiences with the public?
Don Pettit: If a picture is worth a thousand words and we take thousands of pictures that certainly says something in terms of the magnitude of communication we can have in conveying this amazing environment to people on Earth, who are of course, the ones collectively who makes this happen, and we are the lucky ones that get to go into space.
Part of any explorations, when you are going into the frontier and you come back you need to explain to people what the frontier is like, you need to share the stories and experience. Images now are one of the prime ways of doing that. I think the taking of both still images and video in space is not only an important pastime for the astronauts to do, but important to convey to the public that ultimately funds the space program, what is going on up there and how wonderful an environment this is. And eventually our technology will move to the point where people, wholesale, can jump in their rockets and go into this frontier.
Caption: Petit left his camera shutter open for long periods of time to capture star trails and trails of lights on Earth.
Nancy: We sure hope so!
You were an integral part of the SpaceX Dragon grapple and berth, the first commercial spaceship to visit the ISS. After being a part of that, what are your thoughts about the private industry becoming perhaps a vital part of human spaceflight, and in particular for space station operations?
Don Pettit: The commercial space is a natural flow for going into a frontier environment like space. You can see analogs of the wild west in the United States getting settled with a combination of both government programs and government sponsored commercial programs and I think we are going to see the same thing going into space. It’s an important aspect of opening the frontier so that more than just a few government-born programs can operate in this environment.
Nancy: Thanks Don, great to talk with you!
Don Pettit: It’s a pleasure.
I also wanted to ask him a few other questions, but ran out of time. At a reader’s suggestion I was going to ask him about the eggs on the Angry Birds Space video, and how he got them into space. Robert Pearlman from collectSPACE later asked him that question, however, and Pettit replied coyly that all astronauts has some personal items they can bring up, but as to how they got up there, Pettit said he’d leave that one unanswered.
I loved Pettit’s analogy about being an explorer of the frontier and in later interviews he had a great comment about Tweeting and exploring:
Don Pettit: Part of any exploration, like when the Antarctic was explored, they’d return home and tell their stories, spread their experience with those who didn’t have the good fortune get to go, and we are using what is available to us now. If Shackleton had the ability to Tweet, I’m sure he would have Tweeted during his expeditions to Antarctica. On station we have limited time and bandwidth and have help from people on the ground who will help get our information out.
I do get feedback (from his social media posts) and some of the comments will get condensed and sent up to me in an email message, and I take the time to read those. Some bring a pretty big smile to my face. And it is neat to see that you are having an effect, that people are following what you are doing and listening to some of the stories you have to tell.
Pettit talked more about his opportunity for photographing unique astronomical events in space:
Don Pettit: One of the most amazing things is to be able to see something like a comet. We saw a comet, saw a solar eclipse and the transit of Venus, so had a number of fairly rare natural astronomical phenomena. When you see it from space, the vantage point is slightly different and allows you to see the physics of the situation– the shadow of the Moon appears as a dark spot on Earth, and lets you know that, gosh, the guys who wrote the textbooks about this figured all this out without seeing it from this vantage point.
Pettit added that the Transit of Venus was an amazing opportunity, and he brought a full-aperture solar telescope just for the occasion. He said he hopes the images they were able to collect hopefully will be useful in the whole ensemble of images that people took from Earth of the event.
Pettit has now spent a total of 370 days in space, more than a year of his life, and he was asked if he would like to go back:
Don Pettit: I would love to fly back to station again, but there is a bunch of folks standing in line, and everyone needs to wait their turn — there is certain fairness on how this happens. I will throw my name in the hat and get back in line and see what happens. The assignments now go out to about 2015, so if space station has a lifetime to about 2020, about half of all the people going to station have already been assigned.
Later Pettit said: I would go back to space in a nano-second. That’s what I do for a living and give me a few days to get my feet on the ground and I’m ready to go again.
And then he was asked if he would go on a mission away from Earth:
Don Pettit: I’d be willing to immigrate into space and not come back as long as we would have the technology to survive. Going one way to Mars and then running out of air to die is not in the cards. If you went to Mars like people went from continental Europe to the New World, I’d load my family up in the next rocket and we’d immigrate into space.
Caption: Another star-trail image by Pettit.
Another question was if being in space ever gets routine.
Don Pettit: It can be both special and routine. Take your breakfast for example. I found that humans like to have a routine for breakfast, and that gives you certain amount of comfort. But it doesn’t get routine as far as living and working in space. Every day has another eye-opening piece of excitement and you learn something new and that is part of being on a frontier.
About his blogging from the perspective of a zucchini plant in space:
Don Pettit: I wanted to write from the equivalent of a potted plant in the corner, and I wanted to write about it because the technology associated with it is not necessarily straightforward, and I could make it like a gardening manual in space. I decided to write the story of how you grow plants in space from the eyes of a zucchini.
Pettit was asked which transition is harder: going to space or coming back to Earth:
Don Pettit: The adjustment going to space is easier than coming back down to Earth. It takes a while to get rid of this heavy feeling.
Later he said that his first thoughts on landing were, “Welcome back to gravity this is really tough,” and then “when do I get to hug my boys?”
What does the ISS smell like?
Don Pettit: Part machine shop, engine room, laboratory and then when you are cooking dinner and rip open a pouch of stew you can smell a little roast beef.
Caption: The integrated vehicle stack for a deep space human mission concept. Credit: NASA
There are all sorts of details to take into consideration when traveling in deep space, such as where to go, what to do, and how to get back. Since starry-eyed dreamers often don’t take into account the practical realities of putting a human into such an environment, steely-eyed engineers are left to decide the gritty details of such a mission, such as how many pairs of socks are needed. Fortunately, NASA employs engineers who are both steely-eyed and starry-eyed, and their work has just produced an interesting report discussing the human side of deep-space exploration.
The paper, written by Michelle Rucker and Shelby Thompson of Johnson Space Center, focuses on the requirements of a ship that will take the first wave of deep-space human explorers to a near Earth asteroid (NEA), hopefully in the near future. The team stressed that they were only looking at very basic requirements and the paper only provides a basis to work from for more specialized teams that will design individual sub-systems.
To develop the basics, the team had to make some assumptions, and these assumptions are revealing for anyone interested in NASA’s future human exploration plans. The team assumed a 380 day round-trip mission to a NEA, crewed by 4 people, with just 30 days of the mission spent at the asteroid. They assumed the availability of a variety of mission-specific vehicles as well as the ability to perform extra-vehicular activities and dock with the Orion crew module, still under development at NASA. Nevertheless, such assumptions could lead to an exciting mission if they hold throughout the design process.
Caption: Two weeks worth of clothing in a crew transport bag. Credit: NASA
In addition to the assumptions, the team took advantage of knowledge gained from years of working on the International Space Station, and helped in considering details like how many packets of powdered drinks are needed for the duration of the trip as well as how much toothpaste a person uses daily in space. All of these numbers were crunched to derive overall dimensions for the craft.
Although, the sum of these volumes produced an over-sized spacecraft, the team evaluated activity frequency and duration to identify functions that could share a common volume without conflict, reducing the total volume by 24%. After adding 10% for growth, the resulting functional pressurized volume was calculated to be a minimum of 268 cu m (9,464 cu ft) distributed over the functions.
Those dimensions resulted in a 4 story structure totaling almost 280 cubic meters (10,000 cubic feet) of pressurized space that looks like it could have come right off the set of Prometheus.
Caption: Conceptual Deep Space Habitat layout. Credit: NASA/Michelle Rucker and Shelby Thompson.
The various subsystems can be broken into seven different categories. The largest is the equipment section, which takes up 22% of the spacecraft. This space would include things like the environmental control panel and navigation and communications equipment. However, the designers thought that the propulsion system, most likely a solar electric propulsion system, and all required control equipment would be part of an attachable module and would not make up part of the main living space of the habitat.
Mission Operations and Spacecraft Operations make up the next largest chunks of the habitable space, each clocking in at 20%. These areas are reserved for mission specific tasks that are not yet defined and general tasks that are necessary no matter what type of mission the habitat is launched on, such as basic maintenance and repair.
Much consideration was given to the psychological and privacy needs of the inhabitants of the ship and as such about 30% of the total habitable space is devoted to the care of the people on board, with 18% going to “individual” care and 12% going to “group” care.
Caption: Group living and operations area of a conceptual deep space habitat module. Credit: NASA/Michelle Rucker and Shelby Thompson.
Individual care includes basics such as beds, full body cleansing and toilets. Group care is more for multi-person activities, such as a dining hall, food prep and meeting areas. The last 2% of the area on board was allotted to “contingency” planning. It fits its namesake well, as the design team hopes never to have to use the space whose primary purpose is to deal with cabin depressurization, crew fatality or other unforeseeable disaster. There is also a shielded area in the interior of the habitat for refuge for the crew during a solar radiation event.
With the basics laid out, it is now up to the specialist teams to develop the next set of requirements for the sub-systems. The final design will only be completed after a long and iterative process of calculation and re-calculation, design and re-design. Assuming the teams persevere, and the space agency receives adequate funding for developing a deep space mission to an asteroid, NASA’s detail-oriented engineers will have developed a very flexible habitat module to use on the next step of human space exploration that dreamers everywhere can get excited about.
Artist's impression of debris in low Earth orbit. Credit: ESA
Caption: Artist’s impression of debris in low earth orbit Credit: ESA
Space may be big — vastly, hugely, mind-bogglingly big — but the space around Earth is beginning to get cluttered with space junk. This poses a threat, not only to other satellites, space stations and missions, but to us here on Earth as well. While we wrestle with environmental issues posed by human activity on our planet, ESA’s new ‘Clean Space’ initiative aims to address the same issues for its missions, making them greener by using more eco-friendly materials and finding ways to cut down levels of space debris.
Last month ESA and Eurospace organized the Clean Space Eco-design and Green Technologies Workshop 2012 held in the Netherlands. Clean Space is a major objective of Agenda 2015, the Agency’s upcoming action plan. The aim was outlined by ESA Director General Jean-Jacques Dordain: “If we are convinced that space infrastructure will become more and more essential, then we must transmit the space environment to future generations as we found it, that is, pristine.”
The workshop looked at all aspects of space missions, their total environment impact, from concept development to end of life. The impact of regulations regarding substances such as hydrazine, which is used widely as a propellant in space programs and the development of Green Propulsion with propellants that have a reduced toxicity. Environmental friendliness and sustainability often mean increased efficiency, which ESA hopes will give the industry a competitive advantage, so they are looking at technologies which will consume less energy and produce less waste, therefore cutting costs.
Finally they looked at debris mitigation to minimize the impact to the space environment as well as the debris footprint on Earth using controlled and uncontrolled re-entry events and passive de-orbiting systems along with active de-orbiting and re-orbiting systems. They are even considering tethers or sails to help drag abandoned satellites out of low orbit within 25 years. New ‘design for demise’ concepts hope to prevent chunks of satellites surviving re-entry and hitting the ground intact. Active removal of existing debris is also needed, including robotic missions to repair or de-orbit satellites.
6,000 satellites have been launched during the Space Age; less than 1000 of these are still in operation. The rest are derelict and liable to fragment as leftover fuel or batteries explode. Traveling at around 7.5 km/s, a 2 cm screw has a ‘lethal diameter’ sufficient to take out a satellite. Taking the recent loss of the Envisat satellite as an example, this satellite now poses a considerable threat as space junk. An analysis of space debris at Envisat’s orbit suggests there is a 15% to 30% chance of collision with another piece of junk during the 150 years it is thought Envisat could remain in orbit. The satellite’s complexity and size means even a small piece of debris could cause a “fragmentation event” producing its own population of space garbage. Envisat is also too big to be allowed to drift back into the Earth’s atmosphere. The choices seem to be to raise the satellite to a higher, unused orbit, or guide it back in over the Pacific Ocean.
As ESA Director General Jean-Jacques Dordain says “We will not succeed alone; we will need everyone’s help. The entire space sector has to be with us.”
Find out more about ESA’s Clean Space initiative here
Image Caption: Divalia Fossa equatorial trough at Vesta pictured in side by side images showing apparent brightness and topography. The trough encircles most of Vesta and is located just south of the equator. It is about 10 kilometers (6 miles) wide. Rubria and Occia craters straddle Divalia Fossa. The image was snapped on Oct 16, 2011 from an altitude of 700 km (435 mi) from the HAMO mapping orbit. Image Credit: NASA/ JPL-Caltech/ UCLA/ MPS/ DLR/ IDA
“NASA’s Dawn mission to Asteroid Vesta is going exceptionally well”, Dr. Marc Rayman, the mission’s Chief Engineer, told Universe Today in an exclusive interview as the revolutionary spacecraft nears the end of its more than 1 year long super science survey orbiting the giant space rock.
“The Dawn mission is not only going better than we had expected but even better than we had hoped.”
Dawn is Earth’s first mission ever to orbit and explore Vesta up close.
“We have acquired so much more data than we had planned even in late 2011! We have conducted a tremendous exploration of Vesta – the second most massive body between Mars and Jupiter, a giant of the main asteroid belt.”
“Now we are in our second high altitude mapping orbit (HAMO2), which is the final intensive campaign of the Vesta mission,” Rayman told me.
Image Caption: Dawn Orbiting Vesta above the “Snowman” craters. This artist’s concept shows NASA’s Dawn spacecraft orbiting the giant asteroid Vesta above the Snowman craters. The depiction of Vesta is based on images obtained by Dawn’s framing cameras. Dawn is an international collaboration of the US, Germany and Italy. Credit: NASA/JPL-Caltech
Indeed Dawn’s science and maneuvering endeavour’s at Vesta have proceeded so flawlessly that NASA has granted the science team a bonus of 40 days additional time in orbit split between the lower and higher science orbits known as LAMO and HAMO or the Low Altitude Mapping Orbit and the High Altitude Mapping Orbit respectively.
“Our original Vesta departure date was July 17, and now it is about August 26.” Rayman explained.
The bonus time at LAMO has already been completed. Now the team is about to begin the bonus time at HAMO – consisting of two additional mapping cycles beyond the four originally planned.
Each mapping cycle in HAMO2 consists of 10 orbits. Each orbit is about 12.5 hours.
“On July 14, we will complete mapping cycle 4 and begin 5 (of 6). On July 25 we will leave HAMO2 and escape from orbit on August 26. We will stop thrusting several times before escape to take more neat pictures, mostly of the northern hemisphere,” Rayman told me.
“As Dawn revolves, Vesta rotates on its axis beneath it, turning once every 5.3 hours.”
When Dawn arrived in orbit at Vesta in July 2011 the northern polar region was in darkness as the southern hemisphere basked in summer’s glow. Now as Dawn departs Vesta in August, virtually all of the previously unseen and unphotographed northern polar region is illuminated and will be mapped in exquisite detail.
Coincidentally on July 13/14 as HAMO2 Cycle 4 ends, I’ll be presenting a free public lecture about Dawn and NASA’s Planetary and Human Spaceflight programs at the Adirondack Public Observatory.
Image Caption: Asteroid Vesta and Mysterious Equatorial Grooves – from Dawn Orbiter. This full view of the giant asteroid Vesta was taken by NASA’s Dawn spacecraft on July 24, 2011, at a distance of 3,200 miles (5,200 kilometers). This view shows impact craters of various sizes and mysterious grooves parallel to the equator. The resolution of this image is about 500 meters per pixel. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
Why has Dawn been granted an extended mission ?
“Dawn has gone so well that we had consumed not even one day of our 40 days of operations margin,” Rayman stated .
“That allowed us to spend more time in LAMO. We had had some unexpected events to be sure, but we managed to deal with all of them so expeditiously that the entire margin remained intact. Then we received the (entirely unrelated) 40 day extension, which allowed us to leave Vesta later. That came about because of our being able to shorten the flight from Vesta to Ceres, so we could still reach Ceres on schedule in 2015.”
“That 40 days allowed us to spend still ~ 30 more days in LAMO and increase HAMO2 by 10 days to a total of six cycles. We got still more time by finding ways to make the trip from HAMO2 to escape a little more efficiently, and that’s what allowed HAMO2 to be even longer, with the additional eight days of VIR-only observations I described in my most recent Dawn Journal.”
“The summary is that every investigation has been more productive than we could have imagined, and because the exploration of Vesta has gone so well, we have been able to apply our unused margin to get even more out of the mission. It is very very gratifying and exciting.”
So we have a few more weeks to enjoy the wondrous sights of Vesta before Dawn fires up her revolutionary ion thrusters to escape the gravitational tug of Vesta and head off to the dwarf planet Ceres, the largest asteroid in the main belt of our Solar System – and which some have speculated may hold vast caches of water and perhaps even liquid oceans suitable for sustaining life.
…..
July 13/14: Free Public Lectures about NASA’s Mars, Vesta and Planetary Exploration, the Space Shuttle, SpaceX , Orion and more by Ken Kremer at the Adirondack Public Observatory in Tupper Lake, NY.
This quick animation made by astrophotographer Alan Friedman shows a 30-minute view of sunspot 1520, a large region of magnetic activity on the Sun that’s currently aimed directly at Earth. Although 1520 has been quiet for the past couple of days, it’s loaded with a delta-class magnetic field — just right for launching powerful X-class flares our way. There’s no guarantee that it will, but then there’s no guarantee that it won’t either.
(Click the image to play the animation.)
Alan captured the images from his location in upstate New York using a 10″ Astro-Physics scope and PGR Grasshopper CCD. A master at solar photography — several of his hydrogen alpha images have been featured here on Universe Today as well as other popular astronomy news sites — Alan’s work never fails to impress.
A static, color version of sunspot 1520 can be seen here… what Alan calls “a magnetic beauty.”
Although the sunspots don’t change much over the course of the animation, the surrounding texture on the Sun’s photosphere can be seen to shift and move rapidly. These bright kernels are called granules, and are created by convective currents on the Sun. An individual granule typically lasts anywhere from 8 to 20 minutes and can be over 600 miles (1000 km) across.
The overall wavering effect is caused by distortion from Earth’s atmosphere.
While 1520 is facing Earth we’re subject to any flares or CMEs that may erupt from it, potentially sending a solar storm our way. In another week or so it will have rotated safely around the Sun’s limb and eventually dissipate altogether… but then, it is solar maximum and so there’s likely to be more active regions just like it (or even larger!) coming around the bend.
When they do come, there’s a good chance that Alan will grab some pics of those too.
Caption: Richard Branson at the Farnborough International Airshow showing a model of LauncherOne. Credit: Virgin Galactic.
Virgin Galactic’s latest venture is launching small satellites with a new, more affordable launching system called LauncherOne. “The pieces are all in place to transform the business of satellite launch, which will open up space to everyone,” said the founder of Virgin Galactic, Richard Branson. “This new vehicle will change the whole satellite industry and space-based science research.”
LauncherOne is much like the Pegasus system, operated by Orbital Sciences Corporation, which launches a rocket from an aircraft, as was done with NASA’s NuSTAR X-ray observatory. LauncherOne will be attached to the WhiteKnight plane, the mothership for SpaceShipTwo, Virgin’s commercial suborbital passenger ship.
LauncherOne could be used for smaller Earth observation and communications satellites.
Virgin Galactic has hinted previously that they were working on a rocket to put spacecraft into orbit, but they have been focusing on SpaceShipTwo. Branson announced the new launcher at the Farnborough International Airshow in the UK today.
“Small satellite launch is an area ripe for disruption,” said Virgin Galactic CEO George Whitesides. “Miniaturized satellite components and constrained budgets are driving commercial clients, academic users and government agencies all to clamor for an affordable, dedicated launch vehicle. Now,…we’re prepared to fill that void by bringing LauncherOne to market.”
Initial information about LauncherOne is that it would use a two-stage rocket powered by liquid oxygen and kerosene.
It would be capable of launching payloads of up 225kg (500lb) into low-Earth orbits, and for a price below $10 million.
“The cost of putting a satellite into space before Virgin Galactic was around $30-40 million,” Branson said. “We’ll be able to do it for under $10 million, opening up space to thousands of new groups, universities and research programs.”
LauncherOne will be built in California, with test flights starting in 2015 and commercial operations starting in 2016.
“Virgin Galactic’s goal is to revolutionize the way we get to space,” Branson said. “I’m immensely proud of what we have already achieved as we draw near to regular suborbital flights on SpaceShipTwo. Now, LauncherOne is bringing the price of satellite launch into the realm of affordability for innovators everywhere, from start-ups and schools to established companies and national space agencies. It will be a critical new tool for the global research community, enabling us all to learn about our home planet more quickly and affordably.”
Branson said he already has people lined up to book the new launcher. “Even before this official launch we have the largest order book of any new launch vehicle ever,” he said on the Virgin blog.
They’re out there; tiny, extremely faint and incredibly ancient dwarf galaxies with so few stars that scientists call them ‘ghost galaxies.’ NASA’s Hubble Space Telescope captured images of three of these small-fry galaxies in hopes of unraveling a mystery 13 billion years in the making.
Astronomers believe these tiny, ghost-like galaxies spotted alongside the Milky Way Galaxy are among the oldest, tiniest and most pristine galaxies in the Universe. Hubble views reveal that their stars share the same birth date. The galaxies all started forming stars more than 13 billions years ago but then abruptly stopped within just one billion years after the Universe was born.
“These galaxies are all ancient and they’re all the same age, so you know something came down like a guillotine and turned off the star formation at the same time in these galaxies,” said Tom Brown of the Space Telescope Science Institute in Baltimore, Md., the study’s leader. “The most likely explanation is reionization.”
Reionization of the Universe began in the first billion years after the Big Bang. During this time, radiation from the first stars knocked electrons off hydrogen atoms, ionizing the hydrogen gas. This process also allowed hydrogen gas to become transparent to ultraviolet light. This same process may also have squashed star-making in dwarf galaxies, such as those in Brown’s study. These galaxies are tiny cousins to star-making dwarf galaxies near the Milky Way. And because of their small size, just 2,000 light-years across, they were not massive enough to shield themselves from the harsh ultraviolet light of the early Universe which stripped away their meager supply of hydrogen gas, leaving them unable to make new stars.
Astronomers proposed many reasons for the lack of stars in these galaxies in addition to the reioniation theory. Some scientists believed internal events such as supernovae blasted away the gas needed to create new stars. Others suggested that the galaxies simply used up their supply of hydrogen gas needed to make stars.
Brown measured the stars’ ages by looking at their brightness and colors. The stellar populations in these fossil galaxies range from a few hundred to a few thousand stars; some sun-like, some red dwarfs and some red stars larger than our Sun. When evidence showed that the stars were indeed ancient, Brown enlisted the help of Hubble’s Advanced Camera for Surveys to burrow deep within six galaxies to determine when they were born. So far, the team has finished analyzing data for three; Hercules, Leo IV and Ursa Major. The galaxies lie between 330,000 light-years to 490,000 light-years. For comparison, Brown compared the galaxies’ stars with those found in M92, a 13 billion-year-old globular cluster located about 26,000 light-years from Earth. He found they are of similar age.
“These are the fossils of the earliest galaxies in the universe,” Brown said. “They haven’t changed in billions of years. These galaxies are unlike most nearby galaxies, which have long star-formation histories.”
Brown’s discovery could help explain the so-called “missing satellite problem.” Astronomers have observed only a few dozen dwarf galaxies around the Milky Way while computer simulations predict thousands should exist. But perhaps they do exist. The Sloan survey found more than a dozen tiny, star-starved galaxies in the Milky Way’s neighborhood while scanning just a portion of the sky. Astronomers think that dozens more ultra-faint galaxies may lurk undetected with the possibility of thousands of even smaller dwarfs containing virtually no stars.
The tiny galaxies may be star-deprived but they still have an abundance of dark matter, the framework upon which galaxies are built. Normal dwarf galaxies near the Milky Way Galaxy contain ten times more dark matter than ordinary visible matter. Brown explains that these tiny galaxies are now islands of mostly dark matter, unseen for billions of years until astronomers began finding them in the Sloan Survey.
Brown’s results appear in the July 1 issue of the Astrophysical Journal Letters.
Image caption 1: These Hubble images show the dim, star-starved dwarf galaxy Leo IV. The image at left shows part of the galaxy, outlined by the white rectangular box. The box measures 83 light-years wide by 163 light-years long. The few stars in Leo IV are lost amid neighboring stars and distant galaxies. A close-up view of the background galaxies within the box is shown in the middle image. The image at right shows only the stars in Leo IV. The galaxy, which contains several thousand stars, is composed of sun-like stars, fainter, red dwarf stars, and some red giant stars brighter than the sun. Credit: NASA, ESA, and T. Brown (STScI)
Image caption 2: These computer simulations show a swarm of dark matter clumps around our Milky Way galaxy. Some of the dark-matter concentrations are massive enough to spark star formation. Thousands of clumps of dark matter coexist with our Milky Way galaxy, shown in the center of the top panel. The green blobs in the middle panel are those dark-matter chunks massive enough to obtain gas from the intergalactic medium and trigger ongoing star formation, eventually creating dwarf galaxies. In the bottom panel, the red blobs are ultra-faint dwarf galaxies that stopped forming stars long ago. Credit: NASA, ESA, and T. Brown and J. Tumlinson (STScI)
This just in! Astronomers working with the Hubble Space Telescope have spotted a new moon around distant Pluto, bringing the known count up to 5. The image above was released by NASA just minutes ago, showing the Pluto system with its newest member, P5.
This news comes just a couple of weeks shy of the one-year anniversary of the announcement of Pluto’s 4th known moon, still currently named “P4”.
The news was shared this morning by an undoubtedly excited Alan Stern of the Southwest Research Institute (SwRI) on Twitter.
Astronomers estimate P5 to be between 6 and 15 miles (9.6 to 24 km) in diameter. It orbits Pluto in the same plane as the other moons — Charon, Nix, Hydra and P4.
“The moons form a series of neatly nested orbits, a bit like Russian dolls,” said team lead Mark Showalter of the SETI Institute.
A mini-abstract of an upcoming paper lists image sets acquired on 5 separate occasions in June and July. According to the abstract, P5 is 4% as bright as Nix and 50% as bright as P4.
The satellite’s mean magnitude is V = 27.0 +/- 0.3, making it 4 percent as bright as Pluto II (Nix) and half as bright as S/2011 (134340) 1. The diameter depends on the assumed geometric albedo: 10 km if p_v = 0.35, or 25 km if p_v =0.04. The motion is consistent with a body traveling on a near-circular orbit coplanar with the other satellites. The inferred mean motion is 17.8 +/- 0.1 degrees per day (P = 20.2 +/- 0.1 days), and the projected radial distance from Pluto is 42000 +/- 2000 km, placing P5 interior to Pluto II (Nix) and close to the 1:3 mean motion resonance with Pluto I (Charon).
The new detection will help scientists navigate NASA’s New Horizons spacecraft through the Pluto system in 2015, when it makes an historic and long-awaited high-speed flyby of the distant world.
After studying 85 carbonaceous chondrites, supplied by Johnson Space Center and the Meteorite Working Group, they show in a paper released today by Science Express that they likely did not form in the same regions of the solar system as comets because they have much lower deuterium content. They formed closer to the Sun, perhaps in the asteroid belt between Mars and Jupiter. And its that material that rained on early Earth to create the wet planet we know today.
