Space and astronomy news
What’s it like to spend a night at a huge telescope observatory? Jordi Busque recorded a brilliant timelapse of the Very Large Telescope (VLT) and the Atacama Large Millimeter/submillimeter Array (ALMA). What makes this video unique is not only the exotic location in Chile, but the use of sound in the area rather than music.
Continue reading “Amazing Video Timelapse Of Big Telescopes At Work In Chile”
Wow! Rosetta is getting ever-closer to its target comet by the day. This navigation camera shot from Aug. 23 shows that the spacecraft is so close to Comet 67P/Churyumov-Gerasimenko that it’s difficult to fit the entire 2.5-mile (four-kilometer) comet in a single frame.
As the European Space Agency explained, the way that Rosetta is taking pictures is changing — and that’s not only because the spacecraft is searching for a safe touchdown site for its lander, Philae.
“Until now, each NAVCAM image has covered the whole comet in one shot, but now that Rosetta is about 50 km [31 miles] from the comet, the nucleus is close to overfilling the NAVCAM field, and will do as we get even closer,” ESA stated.
“As a result, on Saturday [Aug. 23] we started taking NAVCAM image sequences as small 2 x 2 rasters, such that roughly one quarter of the comet is seen in the corner of each of the four images, rather than all in just one shot.”
ESA also noted there is a delay of about 20 minutes between the first and last images in the sequence, during which time both the comet and Rosetta are moving. This changes how the shadows and other things on the comet appear. ESA hasn’t yet made any software to create composite images, because it’s not needed for navigation (the primary reason the camera is there.)
Source: European Space Agency
While the stars appear unchanging when you take a quick look at the night sky, there is so much variability out there that astronomers will be busy forever. One prominent example is Eta Carinae, a star system that erupted in the 19th century for about 20 years, becoming one of the brightest stars you could see in the night sky. It’s so volatile that it’s a high candidate for a supernova.
The two stars came again to their closest approach this month, under the watchful eye of the Chandra X-Ray Observatory. The observations are to figure out a puzzling dip in X-ray emissions from Eta Carinae that happen during every close encounter, including one observed in 2009.
The two stars orbit in a 5.5-year orbit, and even the lesser of them is massive — about 30 times the mass of the Sun. Winds are flowing rapidly from both of the stars, crashing into each other and creating a bow shock that makes the gas between the stars hotter. This is where the X-rays come from.
Here’s where things get interesting: as the stars orbit around each other, their distance changes by a factor of 20. This means that the wind crashes differently depending on how close the stars are to each other. Surprisingly, the X-rays drop off when the stars are at their closest approach, which was studied closely by Chandra when that last occurred in 2009.
“The study suggests that part of the reason for the dip at periastron is that X-rays from the apex are blocked by the dense wind from the more massive star in Eta Carinae, or perhaps by the surface of the star itself,” a Chandra press release stated.
“Another factor responsible for the X-ray dip is that the shock wave appears to be disrupted near periastron, possibly because of faster cooling of the gas due to increased density, and/or a decrease in the strength of the companion star’s wind because of extra ultraviolet radiation from the massive star reaching it.”
More observations are needed, so researchers are eagerly looking forward to finding out what Chandra dug up in the latest observations. A research paper on this was published earlier this year in the Astrophysical Journal, which you can also read in preprint version on Arxiv. The work was led by Kenji Hamaguchi, who is with NASA’s Goddard Space Flight Center in Maryland.
Source: Chandra X-Ray Observatory
How does microgravity affect your health? One of the chief concerns of NASA astronauts these days is changes to eyesight. Some people come back from long-duration stays in space with what appears to be permanent changes, such as requiring glasses when previously they did not.
And the numbers are interesting. A few months after NASA told Universe Today that 20% of astronauts may face this problem, a new study points out that 21 U.S. astronauts that have flown on the International Space Station for long flights (which tend to be five to six months) face visual problems.
These include “hyperopic shift, scotoma and choroidal folds to cotton wool spots, optic nerve sheath distension, globe flattening and edema of the optic nerve,” states the University of Houston, which is collaborating with NASA on a long-term study of astronauts while they’re in orbit.
NASA is flying an instrument on board the International Space Station that does optical coherence tomography, which acts like a microscope on the eye. The technology looks at things such as pressure in the eye and changes in the optic nerve and retinal structures.
The collaboration with the University of Houston recently won Heidelberg Engineering’s annual 2014 Xtreme Research Award. In the long term, the researchers involved are hoping to figure out what changes to make for long-duration missions. One example could be changing carbon dioxide levels on the station, if that is found to play a role.
Long-term health considerations will be one thing examined closely when an astronaut and a cosmonaut spend a year on the International Space Station in 2015, with their milestone bringing them in a small group of people who have spent a year or more consecutively in space.
Source: University of Houston
Performing observations in Australia is on many astronomers’ bucket lists, and this video timelapse shows you precisely why. Famous, world-class observatories, dark sky and the beautiful desolation of the desert combine in this award-winning sequence shot by Alex Cherney and posted on Vimeo.
Cherney writes that the video “is the result of over three years of work” and was the winner of the 2014 STARMUS astrophotography competition. Here are the observatories that are featured:
An independent investigation committee is looking at why two European navigation satellites are in the wrong orbits following their launch from French Guiana last week.
While the first part of the launch went well, officials said telemetry from the satellites showed that the satellites were not where they were supposed to be. The probe is ongoing, but officials believe it is related to a stage of the Soyuz rocket that hefted the satellites into space.
“According to the initial analyses, an anomaly is thought to have occurred during the flight phase involving the Fregat upper stage, causing the satellites to be injected into a noncompliant orbit,” wrote launch provider Arianespace in an update on Saturday (Aug. 23).
The same day, the European Space Agency added that officials are looking into how the mission would be affected, if at all.
The Galileo satellites, the fifth and sixth of the constellation, are intended to serve as part of a cloud of navigation satellites that would be a European alternative to the United States GPS system. Officials are hoping to launch six to eight more satellites per year until 2017, when 24 satellites and six backups will be ready for full service.
The satellites were supposed to be in a circular orbit, inclined at 55 degrees to the Earth’s equator and have a maximum orbital radius (semi-major axis) of 29,900 km (18,579 miles). Telemetry now shows the satellites are in a non-circular orbit inclined at 49.8 degrees, with a semi-major axis of 26,200 km (16,280 miles).
After 17 years of faithful service, the end is in sight for the Tropical Rainfall Measuring Mission (TRMM). The joint NASA-Japanese mission is out of fuel (except for a small reserve amount for emergencies) and beginning its slow descent back to Earth.
From that fall, the satellite is not going to recover. It’s expected to re-enter the atmosphere and be destroyed around November 2016. The satellite will be shut down around February 2016, depending on how much solar activity pumps up the atmosphere.
“TRMM has met and exceeded its original goal of advancing our understanding of the distribution of tropical rainfall and its relation to the global water and energy cycles,” stated Scott Braun, the mission’s project scientist at NASA’s Goddard Space Flight Center in Maryland.
The satellite was designed to operate at about 250 miles (400 kilometers), and will slowly fall untl it gets to around 75-93 miles (120-150 kilometers), where it will break up.
While there’s no longer enough fuel to keep it at its normal operating altitude, NASA emphasized the satellite will still function well enough to estimate rains, floods and cyclones during the descent. However, its microwave imager will be affected because the field of view changes as the satellite descends.
NASA also pointed out that the successor satellite, the Global Precipitation Measurement (GPM) Core Observatory, is performing well since its launch on Feb. 27 this year.
“The GPM Core Observatory’s area of coverage extends beyond TRMM’s, covering the area from the Arctic Circle to the Antarctic Circle. While this means fewer observations of the tropics, it also means that GPM will be able to observe hurricanes, like Sandy in 2012, that travel north (or south) farther into the mid-latitudes,” NASA wrote.
“GPM will also be able to detect light rain and snowfall, a major source of available fresh water in some regions. The joint NASA/JAXA mission will study rain and snow around the world, joining with an international network of partner satellites to provide global precipitation datasets on half hourly and longer time scales.”
Source: NASA
While this solar peak has been weaker than usual, from time to time we get a moderate punch from the Sun. Here’s an example — what NASA calls a “mid-level” solar flare blasting off the Sun at 8:16 a.m. EDT (1:16 p.m. UTC) yesterday (Aug. 26).
While the related coronal mass ejection can cause auroras high in Earth’s atmosphere and (in more severe cases) cause telecommunications disruptions, in this case the U.S. government isn’t expecting much.
“Given the location of this event, the associated coronal mass ejection is well off the Sun-Earth line and no significant geomagnetic storming is anticipated as a result,” wrote the National Weather Service’s Space Weather Prediction Center in an update today.
NASA says the flare, which was captured by the Solar Dynamics Observatory, is an M5 flare. X-class flares are about 10 times more powerful than M-class ones.
An unrelated solar event recently caused auroras that astronauts spotted from the International Space Station.
Another milestone for the Pluto-bound New Horizons mission — it’s crossing the orbit of Neptune today, as it prepares to fly by Pluto next August. In celebration, NASA is holding two live events at headquarters in Washington, D.C. starting at 1 p.m. EDT (5 p.m. UTC) today, and livestreamed above. More details below the jump.
The panel at 1 p.m. EDT will include:
Between 2 p.m. and 3 p.m. EDT, New Horizons team members will recall what happened when Voyager 2 passed by Neptune 25 years ago, and also talk about where they are working today on the Pluto mission. The members will include:
No injuries are reported after a SpaceX rocket prototype detonated in Texas today (Aug. 22) after an anomaly was found in the rocket, the company said in a statement.
The  Falcon 9 Reusable (F9R) — a successor to the Grasshopper vertical take-off and landing rocket — was completing the latest in a series of ambitious tests that previously saw the prototype successfully testing new steerable fins.
“Today’s test was particularly complex, pushing the limits of the vehicle further than any previous test,” SpaceX said in a statement (which you can read in full below the jump.) “As is our practice, the company will be reviewing the flight record details to learn more about the performance of the vehicle prior to our next test.”
The company said it would provide more updates as it found information. SpaceX founder Elon Musk issued a brief statement of his own on Twitter:
Three engine F9R Dev1 vehicle auto-terminated during test flight. No injuries or near injuries. Rockets are tricky …
— Elon Musk (@elonmusk) August 23, 2014
Below is SpaceX’s statement:
Earlier today, in McGregor, Texas, SpaceX conducted a test flight of a three-engine version of the F9R test vehicle (successor to Grasshopper.) During the flight, an anomaly was detected in the vehicle and the flight termination system automatically terminated the mission.
Throughout the test and subsequent flight termination, the vehicle remained in the designated flight area. There were no injuries or near injuries. An FAA representative was present at all times.
With research and development projects, detecting vehicle anomalies during the testing is the purpose of the program. Today’s test was particularly complex, pushing the limits of the vehicle further than any previous test. As is our practice, the company will be reviewing the flight record details to learn more about the performance of the vehicle prior to our next test.
SpaceX will provide another update when the flight data has been fully analyzed.
Here are some recent Universe Today stories on the rocket: