Mount St. Helens shortly after its eruption in 1980. Credit: Landsat
Turn a camera to a location for four decades, and you can see a lot of change. Streets appear or disappear. Trees grow and eventually, die. Houses spring up and slowly decay.
Landsat is the longest-running Earth observation program, with four decades of observations behind it. Today, to celebrate the launch of Landsat 5 on this day in 1984, here are five Landsat images that helped us better understand the Earth and at times, how humans affect its environment.
Mount St. Helens
When Washington State’s Mount St. Helens exploded in May 1980, it killed 57 people and obliterated much of the surrounding countryside. For American volcanologists, however, St. Helens was an easy target to study both up close and with the Landsat satellite. This 1980 image shows the devastated countryside in the weeks after the eruption. Landsat photos from every year since demonstrate how the area has recovered in the past two decades.
3-D Antarctica
A 3-D map of Antarctica using 1,100 images from the Landsat 7 satellite. Credit: Landsat/USGS
That image up there was years in the making. First, scientists collected 1,100 images of Antarctica using the Landsat 7 satellite. That process took three years, between 1999 and 2001. They combined elevation data and field measurements. Next came the painstaking process of stitching it together. It was finally released to the public in 2007. An unexpected benefit? Spying the continent from space allowed scientists to better track Emperor penguins. That brown stain on the image is actually where the penguins were sitting when the pictures were taken.
Rushing to Kuwait’s rescue
Oil well fires burn in Kuwait during the 1991 Persian Gulf War. Credit: Landsat/USGS
As Iraq pulled out from Kuwait during the Persian Gulf War in 1991, Iraqi troops set fire to some 650 oil wells. The environmental devastation was enormous. This Landsat image, among many others, was crucial for Kuwaiti emergency responders to figure out where the fires were burning and how best to approach them.
Landsat’s Van Gogh image
NASA once compared this image of phytoplankton surrounding Gotland to Vincent Van Gogh’s “Starry Night.” Credit: Landsat/USGS
Are those stars and nebulas we see above? Not quite, but NASA points out it does look very similar to the Vincent Van Gogh image “Starry Night.” That 2005 snapshot from Landsat 7 actually shows phytoplankton surrounding the Swedish island of Gotland in the Baltic Sea. The picture was voted the top snapshot by NASA visitors to the “Earth As Art” contest held in 2012.
Shrinking Aral Sea
The Aral Sea has shrunk to half its size in just 40 years. Credit: Landsat/USGS
The series of Landsat images above show just how much of the Aral Sea disappeared between 1977 and 2006. The body of water, located between Uzbekistan (south) and Kazakhstan, used to be the fourth-largest lake in the world. The Soviets tapped into the sea several decades ago to irrigate the surrounding area. While local authorities are working to reverse the damage, the sea is still about half the size it used to be.
There’s more Landsat magic to come in the next few years. The Landsat Data Continuity Mission left Earth last month and will take more pictures of the Earth in even better resolution than its ancestors. Take a look at its launch video below.
Dragon launches on the SpaceX Falcon 9 on March 1, 2013. Credit: John O'Connor/nasatech
Just after 10 am Eastern time, the SpaceX successfully launched their Dragon capsule on a second resupply mission to the International Space Station. The launch, rocket stage and spacecraft separations went perfectly, but the Dragon experienced an anomaly at about the time the solar arrays should have deployed. The SpaceX webcast announced that the spacecraft experienced a problem and then ended the webcast. NASA TV has not offered information either. We’ll provide more information as soon it becomes available.
Update: (10:44 EST) Elon Musk, SpaceX CEO just tweeted: “Issue with Dragon thruster pods. System inhibiting 3 of 4 from initializing. About to inhibit override.” Then minutes later he added, “Holding on solar array deployment until at least two thruster pods are active.”
See below for a continuation of our live-blogging of the Dragon anomaly, as it happened..
Also, here’s the launch video from launch to separation (note, the separation video is spectacular!):
Dragon carries 18 Draco thrusters for attitude control and maneuvering, so there may be an issue with those. Dragon’s thruster problem may be preventing the spacecraft from going into array deploy attitude, thus preventing array deploy.
Only time will tell if this is a software or hardware problem. The SpaceX press kit describes what needs to happen for solar array deploy:
Dragon separates from Falcon 9’s second stage, and seconds later, Dragon will reach its preliminary orbit. It then deploys its solar arrays and begins a carefully choreographed series of Draco thruster firings to reach the space station.
If Dragon can’t make it to the ISS, then it would need to be decided if and how it can return back to Earth on a good trajectory with limited thruster control.
The SpaceX controllers are obviously working to try and resolve the problem.
Update: 11:10 EST An update from NASA TV at about 11:10 am, said that part of response to problem with Dragon may be reorganizing the burn sequences in order for the spacecraft to be able to approach to the ISS. Musk just tweeted: “About to pass over Australia ground station and command inhibit override.”
Update: 11:25 EST: A statement from SpaceX says that “One thruster pod is running. Two are preferred to take the next step which is to deploy the solar arrays. We are working to bring up the other two in order to plan the next series of burns to get to station.”
Update: 11:42 EST: Elon Musk just tweeted: “Thruster pod 3 tank pressure trending positive. Preparing to deploy solar arrays.” That is good news.
Update: 11:50 EST: Another Tweet from Musk, with some short but sweet news: “Solar array deployment successful” That means they were abe to get at least two of the four thruster pods working, per the minimum requirement. Now, to see if the thruster problem causes any issues with getting to the ISS.
Update: 12:05 EST: Elon Musk continues to be the best source of info. He’s just tweeted, “Attempting bring up of thruster pods 2 and 4.”
We’re assuming that means 1 and 3 are already working, since it was going to take at least 2 pods thrusting to enable solar array deploy.
Update: 12:14 EST: The latest statement from SpaceX : “After Dragon achieved orbit, the spacecraft experienced an issue with a propellant valve. One thruster pod is running. We are trying to bring up the remaining three. We did go ahead and get the solar arrays deployed. Once we get at least 2 pods running, we will begin a series of burns to get to station.”
So, they were able to deploy the arrays with just one thruster pod working, and they are now working to get at least one more working. One question to consider is if the spacecraft and arrays were able to be in the right position to gather sunlight and produce power.
Update: 12:42 EST: According to reports on Twitter, a NASA official has said that three Dragon thruster pods are needed to fly to the ISS, and at this point, only one pod is working.
SpaceX CRS-2 Launch on March 1, 2013. Credit: John O’Connor/nasatech
Update: 2:00 EST: This update from SpaceX: “SpaceX is still working through issues in Dragon’s propulsion system. The mission’s first rendezvous burn was delayed at least one orbit to about 2 p.m. EST.” (which is now)….stay tuned for updates. There will be a press conference sometime today, NASA has said, but has not yet set a specific time.
Update: 2:28 EST: NASA says the Dragon capsule Dragon will no longer be able to make its scheduled rendezvous with the station tomorrow. SpaceX indicated the rendezvous with the ISS will now not happen until at least Sunday morning. There will be a news briefing at 3pm EST.
Communication between the ISS crew and mission control confirms the delay for the rendezvous: “They are making progress recovering their prop system, but it’s not going to be in time to support the rendezvous and capture for tomorrow,” NASA’s spacecraft communicator told the crew. “So that is not going to happen tomorrow.”
“OK, copy, sounds like another off-duty day for us,” said ISS commander Kevin Ford. “We don’t wish that. We wish it gets fixed and gets up here to us. That’s really awesome they’re working their way through the problems. That’s what it’s all about.”
Update: 2:58 EST: Latest Tweet from Elon Musk has good news: “Pods 1 and 4 now online and thrusters engaged. Dragon transitioned from free drift to active control. Yes!!”
Update: 4:11 EST: Here’s a brief synopsis of the press briefing:
During the press conference, Elon Musk indicated there was a blockage in the helium line leading to the oxidizer pressurization system, or perhaps a stuck valve, and the pressure was not high enough to turn on the thrusters. The engineering team cycled the valves several times, using pressure hammering to loosen up and debris that might be stuck in the valves. And now, the pressure is nominal, with all the oxidizer tanks holding the target pressure on all 4 pods, and so Musk said he is hopeful that all the thrusters will be able to work.
Musk said they decided to deploy Dragon arrays before two thrusters were online because the temperature of the array actuators was dropping rapidly. But they also deployed solar arrays partly to mitigate Dragon’s attitude rotation “like a skater extending arms during a spin,” he said.
Musk mentioned the batteries on board had 12-14 hours of life, so deploying the arrays early was not a question of running out of power, but making sure solar arrays didn’t get so cold that they couldn’t deploy later.
NASA’s Mike Suffredini said that at least 3 of the 4 pods have to be operational in order to make an approach to the ISS.
They will make a decision on when to make the rendezvous when they’ve ascertained if the thrusters are working.
Ken Kremer will provide a more detailed update later.
{End of live blogging}
Diagram of the Dragon capsule. Credit: SpaceX
The Dragon is carrying 544 kilograms (1,200 lbs) of scientific experiments and supplies to the space station, and docking was scheduled for Saturday at 6:30 a.m. ET (1100 GMT). That will likely change.
Dragon’s 18 Draco thrusters permit orbital maneuvering and attitude control. They are mounted on four pods: two of the pods contain five thrusters and the other two contain four thrusters. They are powered by nitrogen tetroxide/monomethylhydrazine, and the thrust is used to control the approach to the ISS, power departure from the ISS, and control Dragon’s attitude upon reentry.
As far as the solar arrays, each array is constructed of four panels. Each array measures 6.4 meters (21 feet). The arrays can draw up to 5,000 watts of power, which is about enough power to light about 85 light bulbs. For launch, the arrays are stowed in the unpressurized trunk of the Dragon and are covered by protective fairings. When the fairings jettison, the automated deployment of the arrays is triggered. On the way back to Earth the trunk is jettison and it, along with the arrays, burn up in the atmosphere.
If the arrays do not deploy, battery life on Dragon is only a few hours 12-14 hours, which would not be enough time to keep it alive until it would reach the ISS. It will be about 20 hours from launch until it approaches the ISS, if the mission continues on its scheduled timeline.
You may recall that during the previous mission to the ISS in October 2012 (the second flight to ISS, but first operational SpaceX resupply flight) one of the rocket’s first stage engines suffered an anomaly, where a combustion chamber ruptured. That engine was shut down, and the other engines fired longer to make up for it. The Dragon cargo made it to the correct orbit and continued on the ISS, but a satellite that was launched to orbit as a secondary payload by the Falcon 9 rocket was sent into the wrong orbit as a result of “a pre-imposed safety check required by NASA,” on October 7, and the ORBCOMM OG2 satellite later deorbited and fell back to Earth.
For this launch, all nine engines appeared to work nominally and all stages separated perfectly.
But obviously the SpaceX team saw the thruster problem immediately, as that’s when the webcast was ended.
A poster with a progression of images from Cape Espichel, Sesimbra in Spain. Left is a wide field starscape, center is Orion's deep sky objects and right is a closeup of M42. Credit and copyright: Miguel Claro.
Here’s an awesome sequence of images from skyscape photographer Miguel Claro. These images were captured from Cape Espichel, Sesimbra, Portugal, about 40 km away from Lisbon. This triple sequence poster contains a beautiful widefield view of the well-known winter constellations visible from the northern hemisphere; then a zoom in to focus on Orion; then Claro zooms in even more to find the Great Orion Nebula M42 and M43.
Claro took a single shot for each image with a DSLR camera, using between 10, 35 and 300 mm. “To do this work I´ve used the incredible Vixen Polarie mounting travel, to avoid the Earth rotation, and a Canon 60Da, a camera sensitive to the infrared/H-alpha wavelengths,” Claro said.
Below is an annotated version of the different objects in the image:
An annotated poster with a progression of images from Cape Espichel, Sesimbra in Portugal. Left is a wide field starscape, center is Orion’s deep sky objects and right is a closeup of M42. Credit and copyright: Miguel Claro.
Want to get your astrophoto featured on Universe Today? Join our Flickr group or send us your images by email (this means you’re giving us permission to post them). Please explain what’s in the picture, when you took it, the equipment you used, etc.
SpaceX Falcon 9 rocket before May 2012 blast off from Cape Canaveral Air Force Station, Florida on historic maiden private commercial launch to the ISS. Credit: Ken Kremer/www.kenkremer.com
Kennedy Space Center – All systems are GO and the weather outlook looks spectacular for the March 1 blast off of the privately developed SpaceX Falcon 9 rocket to the International Space Station (ISS).
The Falcon 9 is slated to lift off at 10:10 AM EST with a Dragon capsule loaded with fresh supplies and science gear to continued full up operation and utilization of the ISS.
Right now the weather forecast is at 80% GO on March 1 – with superbly beautiful, clear blue skies here in sunny and comfortably warm Florida from Space Launch Complex 40 at Cape Canaveral Air Force Station.
Large crowds of eager tourists, sightseers and space enthusiasts are already gathering in local hotels – most are sold out including at my hotel where I have been holding well attended ISS star parties during excellent evening viewing opportunities this week.
NASA TV will provide live launch coverage starting at 8 30 AM. SpaceX will also provide a separate feed starting about 40 minutes prior to launch.
The two stage Falcon 9 rocket was rolled out horizontally to the pad late this afternoon (Thursday, Feb. 28) in anticipation of a Friday morning launch. Myself and Dave Dickinson are on-site for Universe Today
The mission dubbed CRS-2 will be only the 2nd commercial resupply mission ever to the ISS.
There are no technical concerns at this time. Saturday March 2 is the back-up launch date in case of a last second scrub. Weather is projected as 80% favorable.
SpaceX President Gwynne Shotwell and NASA officials told me that additional launch opportunities are available Sunday, Monday and Tuesday, if needed, and later until about March 11. After that, the launch team would have to stand down to make way for the next eventual departure of a docked Soyuz and launch of a manned Russian Soyuz capsule with a new three man crew.
SpaceX Falcon 9 rocket liftoff on May 22, 2012 from Space Launch Complex-40 at Cape Canaveral Air Force Station, Fla., on the first commercial mission to the International Space Station. Credit: Ken Kremer
The SpaceX Dragon capsule is carrying about 1,200 pounds of vital supplies and research experiments for the six man international crew living aboard the million pound orbiting outpost.
SpaceX is under contract to NASA to deliver over 44,000 pounds of cargo to the ISS during a dozen flights over the next few years at a cost of about $1.6 Billion.
The capsule is fully loaded Shotwell told me. An upgraded Falcon 9 will be used in the next launch that will allow for a significant increase in the cargo up mass, Shotwell elaborated.
The Dragon is due to dock with the ISS in record time some 20 hours after blast off.
NASA Administrator Charles Bolden addresses the media at SpaceX's main hangar in Cape Canaveral, FL. The sequester will affect both NASA and SpaceX. Credit: NASA.
It seems the US in not going to avoid the sequester — the $85 billion worth of federal spending cuts due to kick in March 1, 2013. There will be across the board cuts to government agencies, applying equally to defense and non-defense spending, and will affect services from meat inspections to air traffic control. In some cases, federal workers will be furloughed or could stand to lose as much as 20 percent of their pay. One question no one can answer is how long it will take for Congress and the Obama administration to come to an agreement on a package that would reduce the deficit.
But in the near term, how will it affect NASA?
“Sequestration would significantly set back the ambitious space exploration plan the President and Congress have asked NASA to carry out,” NASA Administrator Charlie Bolden said in a message to NASA employees this week. “These damaging cuts would slash roughly 5 percent from the agency’s current annual budget during the remaining seven months of the 2013 fiscal year, a loss of about $726 million from the President’s budget request. This could further delay the restarting of human space launches from U.S. soil, push back our next generation space vehicles, and hold up development of new space technologies.
In hard numbers, NASA’s overall budget would drop to $16.9 billion, down from the $17.8 billion Congress approved last year.
NASA civil servants are safe from furloughs, but NASA contractors will see cuts in their contracts.
In a press conference on Feb. 28, preceding the scheduled March 1 launch of the SpaceX Dragon capsule to the ISS, NASA’s Space Station Manager Mike Suffredini said the ISS would not be impacted very much. With humans on board the ISS, there can be no cuts in operations that would endanger the crew. While Sufferdini didn’t say so, if the cuts continue long-term to NASA, there likely would be an impact to science being done, and perhaps eventually crew size.
Spending on the commercial crew program might take one of the biggest hits, and would be reduced to $388 million, which is $18 million less than it is currently spending and $441.6 million less than the agency had been planning to spend in 2013. Boeing, Sierra Nevada, and SpaceX are all under contract to meet performance milestones to deliver cargo and ultimately crew (by 2017) to the International Space Station.
In a separate letter to Senate Appropriations Committee Chairwoman Barbara Mikulski, (D-MD) Bolden said NASA’s commercial crew partners would be affected by this summer, as NASA would no longer be able to fund upcoming events such as a test of Boeing’s CST-100 orbital maneuvering and attitude control engine in July, a September review of an in-flight abort test SpaceX plans to conduct in April 2014, and an October integrated system and safety analysis review of Sierra Nevada’s DreamChaser space plane.
Also at the SpaceX press conference on Feb. 28, SpaceX President Gwynne Shotwell said the specifics of how the sequestration will affect her company is not yet known, but it will likely impact some of their milestones if the budget issues aren’t resolved soon.
Howard Bloom, founder of the Space Development Steering Committee, said these cuts to commercial crew would be a disaster, delaying when US astronauts could launch on US rockets, and would just “shovel” money to Russia.
“This nip and tuck may result in a period of an additional one to two years in which America cannot get astronauts to the International Space Station on our own launch vehicles,” he said in a statement sent to Universe Today. “But we are committed to manning the Space Station. How will we do it? Using Russian Soyuz capsules. At a price of $63 million paid to the Russians for each American passenger– a total of $350-400 million per year.”
Even worse, Bloom said, sequestration could eliminate one of more of the companies working on American launch vehicles, and the result would be “less competition and a potentially higher cost per launch once a new vehicle comes into service.”
Science and research will also be affected, with reductions of $51.1 million below the FY 2013 budget request for astrophysics and science, meaning funding for new missions such as Explorer and Earth Venture Class will be cut, decreasing mission selections by 10 to 15 percent, resulting in lower funding levels for new activities and causing some launch delays. There will also be a reduction in the number of science flight opportunities such as those for college and high school students, and the elimination of Centennial Challenges funding to for any new prizes.
NASA’s Space Technology Program would be cut by $24 million to $550 million instead of $699 million, and any updates or construction at NASA facilities would be centers would be canceled. This may impact updates at Kennedy Space Center for infrastructure needed for NASA’s Space Launch System (SLS), the Orion Multi-Purpose Crew Vehicle, and other programs.
“We will continue to keep you informed as we learn more about issues surrounding the potential sequestration,” Bolden said in his email to NASA employees. Dr. Elizabeth Robinson, Agency Chief Financial Officer, and her staff in the Office of the Chief Financial Officer here at NASA HQ will be following up with the Officials in Charge regarding our plans for implementing sequestration and how those plans will affect NASA’s day-to-day operations. Please feel free to contact her or her staff with questions or concerns.”
Clouds of cosmic dust in the region of Orion. Credit: ESO
The building blocks of life could have their beginnings in the tiny icy grains that make up the gas and dust found between the stars, and those icy grains could be the key to understanding how life can arise on planets. With help from students, researchers have discovered an important pair of prebiotic molecules in the icy particles in interstellar space. The chemicals, found in a giant cloud of gas about 25,000 light-years from Earth may be a precursor to a key component of DNA and another may have a role in the formation of an important amino acid.
“We found the ultimate prebiotic of prebiotic molecules,” said Anthony Remijan, of the National Radio Astronomy Observatory (NRAO).
Using the Green Bank Telescope (GBT) in West Virginia, researchers found a molecule called cyanomethanimine, which produces adenine, one of the four nucleobases that form the “rungs” in the ladder-like structure of DNA. The other molecule, called ethanamine, is thought to play a role in forming alanine, one of the twenty amino acids in the genetic code.
Previously, scientists thought such processes took place in the very tenuous gas between the stars. The new discoveries, however, suggest that the chemical formation sequences for these molecules occurred not in gas, but on the surfaces of ice grains in interstellar space.
“Finding these molecules in an interstellar gas cloud means that important building blocks for DNA and amino acids can ‘seed’ newly-formed planets with the chemical precursors for life,” said Remijan.
In each case, the newly-discovered interstellar molecules are intermediate stages in multi-step chemical processes leading to the final biological molecule. Details of the processes remain unclear, but the discoveries give new insight on where these processes occur.
“We need to do further experiments to better understand how these reactions work, but it could be that some of the first key steps toward biological chemicals occurred on tiny ice grains,” Remijan said.
The discoveries were made possible by new technology that speeds the process of identifying the “fingerprints” of cosmic chemicals. Each molecule has a specific set of rotational states that it can assume. When it changes from one state to another, a specific amount of energy is either emitted or absorbed, often as radio waves at specific frequencies that can be observed with the GBT.
New laboratory techniques have allowed astrochemists to measure the characteristic patterns of such radio frequencies for specific molecules. Armed with that information, they then can match that pattern with the data received by the telescope. Laboratories at the University of Virginia and the Harvard-Smithsonian Center for Astrophysics measured radio emission from cyanomethanimine and ethanamine, and the frequency patterns from those molecules then were matched to publicly-available data produced by a survey done with the GBT from 2008 to 2011.
A team of undergraduate students participating in a special summer research program for minority students at the University of Virginia (U.Va.) conducted some of the experiments leading to the discovery of cyanomethanimine.
“This is a pretty special discovery and proves that early-career students can do remarkable research,” said Books Pate, a U. Va professor who mentored the students.
Two giant swaths of radiation, known as the Van Allen Belts, surrounding Earth were discovered in 1958. In 2012, observations from the Van Allen Probes showed that a third belt can sometimes appear. The radiation is shown here in yellow, with green representing the spaces between the belts. Credit: NASA/Van Allen Probes/Goddard Space Flight Center
In September of 2012, scientists with the newly launched Van Allen Probes got permission to turn on one of their instruments after only three days in space instead of waiting for weeks, as planned. They wanted to turn on the Relativistic Electron Proton Telescope (REPT) so that its observations would overlap with another mission called SAMPEX (Solar, Anomalous, and Magnetospheric Particle Explorer), that was soon going to de-orbit and re-enter Earth’s atmosphere.
Now, they are very glad they did, as something happened that no one had ever seen before. A previously unknown third radiation belt formed in the Van Allen Radiation Belts that encircle Earth. The scientist watched – in disbelief – while their data showed the extra belt forming, then suddenly disappear, like it had been cut away with a knife. They have not yet seen a recurrence of a third belt.
“First we thought our instruments weren’t working correctly,” said Dan Baker, a member of the Van Allen Probes team from the University of Colorado at Boulder, “but we quickly realized we were seeing a real phenomenon.”
What happened is that shortly before REPT was turned on, solar activity on the Sun had sent energy toward Earth that caused the radiation belts to swell. The energetic particles then settled into a new configuration, showing an extra, third belt extending out into space.
“By the fifth day REPT was on, we could plot out our observations and watch the formation of a third radiation belt,” says Shri Kanekal, the deputy mission scientist for the mission. “The third belt persisted beautifully, day after day, week after week, for four weeks.”
This graph shows energetic electron data gathered by the Relativistic Electron-Proton Telescope (REPT) instruments, on the twin Van Allen Probes satellites in eccentric orbits around the Earth, from Sept. 1, 2012 to Oct. 4, 2012 (horizontal axis). It shows three discrete energy channels (measured in megaelectron volts, or MeV). The third belt region (in yellow) and second slot (in green) are highlighted, and exist up until a coronal mass ejection (CME) destroys them on Oct. 1. The vertical axis in each is L*, effectively the distance in Earth radii at which a magnetic field line crosses the magnetic equatorial plane. Credit: LASP
Since their discovery in 1958, we’ve known that the Van Allen radiation belt is composed of two donut-shaped layers of energetic charged particles around the planet Earth, held in place by its magnetic field.
The scientists are now incorporating what they saw into new models of the radiation belts – a region that can sometimes swell dramatically in response to incoming energy from the Sun, impacting satellites and spacecraft or pose potential threats to human space flight.
The belts are normally between 200 to 60,000 kilometers above Earth; the new ring was much further out.
Launched on August 30, 2012 as the Radiation Belt Storm Probes mission, the twin probes were renamed in honor of the belts’ discoverer, astrophysicist James Van Allen. Observations of the belts have shown they are dynamic and mysterious. However, this type of dynamic three-belt structure was never seen, or even considered, theoretically.
A coronal mass ejection (CME) from the Sun on August 31, 2012, the event that caused a third ring to form in the Van Allen radiation belts. Credit: NASA
The Energetic Particle, Composition, and Thermal Plasma (ECT) suite of instruments on board the probes were designed to help understand how populations of electrons moving at nearly the speed of light and penetrating ions in space form or change in response to variable inputs of energy from the Sun.
Already, what the team has learned is re-writing the textbooks of what is known about the Van Allen belts.
“These events we’ve recorded are extraordinary and are already allowing us to refine and confirm our theories of belt dynamics in a way that will lead to predictability of their behavior,” said astrophysicst Harlan Spence, principal investigator for the ECT, “which is important for understanding space weather and ultimately for the safety of astronauts and spacecraft that operate within such a hazardous region of geospace.”
At a press briefing today, the team was asked why this third ring had never been observed before.
“We’ve never had the capability before to see something like this, said Nicky Fox, Van Allen Probes deputy project scientist. “The fact that we had such an amazing discovery within days of turning them on shows we still have mysteries to discover and explain. What the Van Allen Probes have shown is that the advances in technology and detection made by NASA have already had an almost immediate impact on basic science.”
Baker added, “As the philosopher Yogi Bera once said, you can observe a lot just by looking. This shows that when you open new eyes on the Universe you can invariably find new things.”
The team will be seeking to understand what the third ring mean for astronauts and satellites, even though the new ring is farther out, the regions in Earth orbit are magnetically connected to the new region that formed.
“Knowing more about this and understanding more about the belt is important for having better models and being able to predict the lifetimes of spacecraft,” said Fox.
“The rings, satellites, the space station are all affected by space weather,” said Mona Kessel, Van Allen Probes program scientist. “We don’t completely understand what we’ve seen, but we are modeling it and trying to piece this all together, so stay tuned.”
The team has published a paper in the journal Science.
Scientists have known about cosmic rays for a century. But these high-energy subatomic particles, which stream through space at nearly the speed of light and crash into the Earth’s upper atmosphere, have been mostly a mystery. The primary reason: researchers have been unable to tell where they come from, or how they’re born. But new research has shed new light on the origins of cosmic rays: supernovae. (Read our article about this discovery).
Today, Thursday, Feb. 28,at 20:00-20:30 UTC (12:00-12:30 p.m. PST, 3:00 pm EST) Dr. Stefan Funk of the Kavli Institute for Particle Astrophysics and Cosmology (KIPAC) will answer questions from the web. He led the research team that was able to track gamma rays — the most energetic form of electromagnetic radiation, or light — back to the remnants of supernova explosions, using the Fermi Gamma Ray Telescope. The finding offers the first astrophysical evidence for how cosmic rays are produced, as well as where they are generated: in the shock waves that emanate from an exploded star. Continue reading “Cosmic Rays and Exploding Stars”
This image from the NACO system on ESO’s Very Large Telescope shows a candidate protoplanet in the disc of gas and dust around the young star HD100546. Credit: ESO.
Astronomers have taken what is likely the first-ever direct image of a planet that is still undergoing its formation, embedded in its “womb” of gas and dust. The protoplanet, about the size of Jupiter, is in the disc surrounding a young star, HD 100546, located 335 light-years from Earth.
If this discovery is confirmed, astronomers say this it will greatly improve our understanding of how planets form and allow astronomers to test the current theories against an observable target.
“So far, planet formation has mostly been a topic tackled by computer simulations,” said Sascha Quanz, from ETH Zurich in Switzerland, who led an international team using the Very Large Telescope to make the observations. “If our discovery is indeed a forming planet, then for the first time scientists will be able to study the planet formation process and the interaction of a forming planet and its natal environment empirically at a very early stage.”
The protoplanet appears as a faint blob in the circumstellar disc of HD 100546, a well-studied star, and astronomers have already discovered other protoplanets orbiting this star. In 2003, astronomers used a technique called “nulling interferometry” to reveal not only the planetary disk, but also discovered a gap in the disk, where a Jupiter-like planet is probably forming about six times farther form the star than Earth is from the Sun. This newly found planet candidate is located in the outer regions of the system, about ten times further out.
Loading player…
The team used the VLT along with a near-infrared coronograph in an adaptive optics instrument called NACO, which enabled them to suppresses the bright light of the star, combined with pioneering data analysis techniques.
The current theory of planet formation is based mostly on observations of our own solar system. Since 1995, when the first exoplanet around a Sun-like star was discovered, several hundred planetary systems have been found, opening up new opportunities for scientists studying planetary formation. But until now, none have been “caught in the act” in the process of being formed, while still embedded in the disc of material around their young parent star.
This composite image shows a view from the NASA/ESA Hubble Space Telescope (left) and from the NACO system on ESO’s Very Large Telescope (right) of the gas and dust around the young star HD 100546. The Hubble visible-light image shows the outer disc of gas and dust around the star. The new infrared VLT picture of a small part of the disc shows a candidate protoplanet. Both pictures were taken with a special coronagraph that suppresses the light from the brilliant star. The position of the star is marked with a red cross in both panels. Credit: ESO/NASA/ESA/Ardila et al.
But in studying the disc around HD 100546, astronomers have spotted several features that support the current theory that giant planets grow by capturing some of the gas and dust that remains after the formation of a star. They have seen structures in the dusty circumstellar disc, which could be caused by interactions between the planet and the disc, as well as indications that the surroundings of the protoplanet are being heated up by the formation process.
The astronomers are doing follow-up observations to confirm the discovery, as it is possible that the detected signal could have come from an unrelated background source, or it could possibly be a fully formed planet which was ejected from its original orbit closer to the star. But the researchers say the most likely explanation is that this is actually the first protplanet that has been directly imaged.
The comet photographed with a 300mm lens. Both the main dust tail and the shorter, fainter Type III dust tail are seen. Credit: Michael Mattiazzo
Brand new photos from amateur astronomers Michael Mattiazzo and Jim Gifford, both of Australia show the current view of Comet C/2011 L4 PANSTARRS down under, and gives sky watchers in the northern hemisphere hope for great views of in little more than a week. The comet has been brightening steadily and now shines around magnitude 2.6, just a little fainter than the stars of the Big Dipper. More images below:
Comet L4 PANSTARRS from Castlemaine, Victoria, Australia on February 28 through an 11-inch telescope. Click for more photos. Credit: Michael Mattiazzo
On February 28, Mattiazzo spotted the comet and a small portion of its dust tail in evening twilight 6 degrees above the western horizon. Using large binoculars he could trace the tail to 1.5 degrees or three lunar diameters. PANSTARRS also has a second fainter dust tail, called a Type III tail, composed of heavier dust particles, dimly visible in the photo below alongside the brighter Type II tail.
Comet L4 PANSTARRS low in the western sky over Bridgetown, Western Australia Feb. 27, 2013. Click for more photos. Details: 400mm lens, 4-second exposure at ISO 5000. Credit: Jim Gifford
A third ion tail, while not currently visible with the naked eye, shows up well in photographs. Dust tails form when the heat of the sun vaporizes dust-laden ices in the comet’s nucleus; solar photons – literally light itself – gently pushes the dust away from the comet’s head into a long, beautiful tail. Gases like carbon monoxide and cyanogen, which are normally neutral, get their energy levels pumped up by the sun’s ultraviolet light, shed their outer electrons and become “ionized.” The same UV light causes the gases to fluoresce a pale blue.
Comets often develop two tails as they near the sun – a curved dust tail and straight, ion tail. Dust tails reflect sunlight and appear yellowish. Ion tails glow blue when comet gases are ionized by UV light from the sun and re-emit it as blue. Credit: NASA
Dust tails generally follow the comet’s curving orbit and assume the shape of a gently-curved arc; ion tails are straight as a stick and point directly away from the sun. Once carbon monoxide molecules have been ionized, they’re susceptible to the magnetic force that flows from the sun as part of the solar wind. The wind with its entrained solar magnetism sweeps by the comet at some 300 miles per second (500 km/sec.) and blows the ion tail straight back exactly opposite the Sun.
With PANSTARRS sprouting tails right and left and peak brightness predictions still around magnitude 1 or 2, get ready for this herald of the new season.
Here’s bascially a naked-eye view of PANSTARRS, taken by Dave Curtis on February 22, 2013 from Dunedin, New Zealand. “The comet was just visible with the naked eye in the twilight,” Dave said. It was taken with a Canon 5D3 and a 70-200mm lens at 70mm: Comet PanSTARRS on feb. 22, 2013 from Dunedin, New Zealand. Credit: Dave Curtis.
