We keep saying this: the universe is more complex than it appears. Conventional thinking in galaxy research postulates that spiral galaxies have star-forming areas, while ellipticals do not due to a lack of gas. While this thinking has been debunked, there’s now emerging research showing a “green valley” of galaxies somewhat in between these two types.
Basically, the research (which includes participation from citizen scientists in the Galaxy Zoo project) is showing that there are two different populations of “green” galaxies, between ellipticals and spirals. Further, what happens to star formation based upon gas in the area.
“In this paper, we take a look at the most crucial event in the life of a galaxy: the end of star formation. We often call this process ‘quenching’ and many astrophysicists have slightly different definitions of quenching. Galaxies are the place where cosmic gas condenses and, if it gets cold and dense enough, turns into stars. The resulting stars are what we really see as traditional optical astronomers,” wrote Kevin Schawinski, a Ph.D. student at the University of Oxford who is on the Galaxy Zoo team, in a blog post.
“Not all stars shine the same way though: stars much more massive than our sun are very bright and shine in a blue light as they are very hot. They’re also very short-lived. Lower mass stars take a more leisurely pace and don’t shine as bright (they’re not as hot). This is why star-forming galaxies are blue, and quiescent galaxies (or ‘quenched’ galaxies) are red: once star formation stops, the bluest stars die first and aren’t replaced with new ones, so they leave behind only the longer-lived red stars for us to observe as the galaxy passively evolves.”
Hey, all you astro-photographers/videographers out there: were you shooting the Moon back on September 11, 2013? You may want to review your footage and see if you captured a bright flash which occurred at about 20:07 GMT. Astronomers say a meteorite with the mass of a small car slammed into the Moon at that time and the impact produced a bright flash, and it even would have been easy to spot from the Earth.
According to astronomers Jose M. Madiedo, from the University of Huelva and Jose L. Ortiz, from the Institute of Astrophysics of Andalusia both in Spain, this impact was the longest and brightest confirmed lunar impact flash ever observed, as the “afterglow” of the impact remained visible for 8 seconds.
The astronomers think the bright flash was produced by an impactor of around 400 kg with a width of between 0.6 and 1.4 meters. The rock hit may have hit Mare Nubium at about 61,000 kilometers per hour (38,000 miles per hour) — although the uncertainty of the impact is fairly high, the team says in their paper. But if it is as high as they think, it may have created a new crater with a diameter of around 40 meters. The impact energy was equivalent to an explosion of roughly 15 tons of TNT.
This beats the previous largest impact seen – which occurred just six months earlier in March 2013 – which was estimated to pack as much punch as 5 tons of TNT. Astronomers that explosion was caused by a 40 kg meteoroid measuring 0.3 to 0.4 meters wide, traveling about 90,000 km/hr (56,000 mph.)
How often does an asteroid hit the Moon? Astronomers actually aren’t very sure.
On average, 33 metric tons (73,000 lbs) of meteoroids hit Earth every day, the vast majority of which harmlessly ablates or burns up high in Earth’s atmosphere, never making it to the ground. The Moon, however, has little or no atmosphere, so meteoroids have nothing to stop them from striking the surface.
The lunar impact rate is so uncertain because observations for objects in the mass range of visible impacts from Earth are quite few. But now, astronomers have set up networks of telescopes that can detect them automatically. NASA has the Automated Lunar and Meteor Observatory (ALaMO) at Marshall Space Flight Center, and the Spanish telescopes are part of the Moon Impacts Detection and Analysis System (MIDAS) system.
Lunar meteors hit the ground with so much kinetic energy that they don’t require an oxygen atmosphere to create a visible explosion. The flash of light comes not from combustion but rather from the thermal glow of molten rock and hot vapors at the impact site.
This thermal glow can be detected from Earth as short-duration flashes through telescopes. Generally, these flashes last just a fraction of a second. But the flash detected on September 11, 2013 was much more intense and longer than anything observed before.
“Our telescopes will continue observing the Moon as our meteor cameras monitor the Earth’s atmosphere,” said Madiedo and Ortiz in a press release. “In this way we expect to identify clusters of rocks that could give rise to common impact events on both planetary bodies. We also want to find out where the impacting bodies come from.”
Looking at the power of the Chelyabinsk meteor (which struck a year ago and is visible starting around 1:15 in the video above) is still terrifying all these months later. Happily for those of on Earth worried about these big space rocks, the world’s space agencies are taking the threat seriously and are starting to implement new tracking systems to look out for more threatening space rocks.
“It was a pretty nasty event. Luckily, no one was killed but it just shows the sort of force that these things have,” said Alan Harris, senior scientist of the DLR Institute of Planetary Research in Berlin, in this new European Space Agency video.
An asteroid that is only about 100 meters (328 feet) in diameter, for example, “could actually completely destroy an urban area in the worst case. So those are the things we’re really looking out for and trying to find ways to tackle.”
Check out the video for some examples of how the Europeans are talking about dealing with this problem, including a fun comparison to cosmic billiards and a more serious discussion on how to shove these rocks aside if they were on a collision course with our planet.
A big challenge of making history “real” to students is finding a way to make it identifiable. Back in the early days of space exploration, it seemed every launch was on TV and every step to the moon extensively documented on radio, television and other media of the day. In an age where we just pull what we want off of social media and YouTube, the sense of excitement must be hard to convey to younger students.
To bring the inspiration of Apollo 11 to a younger audience, one high school teacher in Maryland took it upon himself to write a play for secondary school students — including much of the original transcript, right down to the “nouns” and “verbs” of the computers the astronauts used.
Richard Zmuda, who teaches in Annapolis, first came up with the idea three years ago after giving a National Honor Society speech to high schoolers where he cited alumni to the students, such as Apollo 11 lunar module pilot Buzz Aldrin.
“I had researched Aldrin for the speech and learned some fascinating details about him personally and about the mission in general,” Zmuda stated. “I realized that, while as a young boy I was able to watch on television Neil Armstrong’s first steps on the moon, none of the students could even remotely share in that experience. Yet it was one of the most important events in the history of mankind.”
The result is a remarkably accurate adaptation of the mission transcript, and one that would be an interesting challenge for young thespians to bring to the stage. There are actual lines of dialog that sound close to what an astronaut of the day would say, such as “Your Co-Elliptic Sequence Initiation Time of Ignition: 125:19:3470.” Teaching the students how to convey a sense of drama, while staying true to the script, would be a fun exercise. It also would require some research so that the students understand what they’re talking about, which is likely the point that Zmuda wanted to convey.
That’s not to say that every line of dialog is that technical. Zmuda works to bring out the drama in several parts of the mission, including how Aldrin initially missed his first test “jump” back on to the lunar ladder and banged his shins against a rung. The staged Aldrin exclaims to the audience, “Well, at least I can say I was the first person to actually PEE on the moon,” something the real person never came close to saying. In a dramatic sense, however — especially given the age of the audience — this was a fun way to show how serious the situation could have been if Aldrin had more trouble getting back up.
Even more interesting is Zmuda’s decision to keep the actors to between four and seven people — three astronauts and either a single person as CapCom in Mission Control, or three people representing the different shifts. This focuses the bulk of the attention on the astronauts, although “Houston” is intended to act as a dramatic foil during the frequent communications blackouts (which did happen in the real mission, too). It also makes it easy for a small drama class to stage the play.
The Apollo 11 adaptation is a fun read for space geeks, and likely is a good tool for teaching history at the high school level and above. Although the script is very technical at times, teaching students how to read this material can be equated to learning how to understand Shakespeare, or to deliver foreign words on stage. It’s a great effort by Zmuda, and hopefully will teach a few students about what the landing represented to space exploration.
The Earth has a single moon, while Saturn has more than 60, with new moons being discovered all the time. But here’s a question, can a moon have a moon? Can that moon’s moon have its own moon? Can it be moons all the way down?
First, consider that we have a completely subjective idea of what a moon is. The Moon orbits the Earth, and the Earth orbits the Sun, and the Sun orbits the center of the Milky Way, which orbits within the Local Group, which is a part of the Virgo Supercluster. The motions of objects in the cosmos act like a set of Russian nesting dolls, with things orbiting things, which orbit other things. So maybe a better question is: could any of the moons in the Solar System have moons of their own? Well actually, one does.
Right now, NASA’s Lunar Reconnaissance Orbiter is happily orbiting around the Moon, photographing the place in high resolution. But humans sent it to the Moon, and just like all the artificial satellites sent there in the past, it’s doomed. No satellite we’ve sent to the Moon has ever orbited for longer than a few years before crashing down into the lunar surface. In theory, you could probably get a satellite to last a few hundred years around the Moon.
But why? How come we can’t make moons for our moon to have a moon of it’s own for all time? It all comes down to gravity and tidal forces. Every object in the Universe is surrounded by an invisible sphere of gravity. Anything within this volume, which astronomers call the “Hill Sphere”, will tend to orbit the object.
So, if you had the Moon out in the middle of space, without any interactions, it could easily have multiple moons orbiting around it. But you get problems when you have these overlapping spheres of influence. The strength of gravity from the Earth tangles with the force of gravity from the Moon.
Although a spacecraft can orbit the Moon for a while, it’s just not stable. The tidal forces will cause the spacecraft’s orbit to decay until it crashes. But further out in the Solar System, there are tiny asteroids with even tinier moons. This is possible because they’re so far away from the Sun. Bring these asteroids closer to the Sun, and someone’s losing a moon.
The object with the largest Hill Sphere in the Solar System is Neptune. Because it’s so far away from the Sun, and it’s so massive, it can truly influence its environment. You could imagine a massive moon distantly orbiting Neptune, and around that moon, there could be a moon of its own. But this doesn’t appear to be the case.
NASA is considering a mission to capture an asteroid and put it into orbit around the Moon. This would be safer than having it orbit the Earth, but still keep it close enough to extract resources. But without any kind of orbital boost, those tidal forces will eventually crash it onto the Moon. So no, in our Solar System, we don’t know of any moons with moons of their own. In fact, we don’t even have a name for them. What would you suggest?
Hosts: Fraser Cain & Scott Lewis
Astronomers: David Dickinson, Gary Gonella, James McGee, Mike Simmons, Roy Salisbury, Shahrin Ahmad, Tom Nathe
Tonight’s views:
Jupiter with a nice view of the red spot, Venus approaching zenith, Bubble Nebula, the Pleiades, Orion Nebula, Horsehead Nebula, Flame Nebula, Running Man Nebula, the Moon, the Sun, the ISS (photo), the Rosette Nebula, Orion again, M33, Sunspots, Rosette again, California Nebula (multiple views), M81 & M82, Planet “X” (?!?), Andromeda, Flame Nebula again
We hold the Virtual Star Party every Sunday night as a live Google+ Hangout on Air. We begin the show when it gets dark on the West Coast. If you want to get a notification, make sure you circle the Virtual Star Party on Google+. You can watch on our YouTube channel or here on Universe Today.
Chang’e-3/Yutu Timelapse Color Panorama
This newly expanded timelapse composite view shows China’s Yutu moon rover at two positions passing by crater and heading south and away from the Chang’e-3 landing site forever about a week after the Dec. 14, 2013 touchdown at Mare Imbrium. This cropped view was taken from the 360-degree timelapse panorama. See complete 360 degree landing site timelapse panorama herein and APOD Feb. 3, 2014. . Chang’e-3 landers extreme ultraviolet (EUV) camera is at right, antenna at left. Credit: CNSA/Chinanews/Ken Kremer/Marco Di Lorenzo – kenkremer.com.
See our complete Yutu timelapse pano at NASA APOD Feb. 3, 2014: http://apod.nasa.gov/apod/ap140203.htm
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The world famous and hugely popular ‘Yutu’ rover entered its 3rd Lunar night time hibernation period this weekend as planned, but serious technical troubles persist that are hampering science operations Chinese space managers confirmed.
“China’s lunar rover Yutu entered its third planned dormancy on Saturday, with the mechanical control issues that might cripple the vehicle still unresolved,” reports Xinhua, China’s official government news agency, in a mission status update newly released today (Feb. 23).
Yutu went to sleep on Saturday afternoon, Feb. 22, local Beijing time, according to China’s State Administration of Science, Technology and Industry for National Defence (SASTIND), responsible for the mission.
The companion Chang’e-3 lunar lander entered hibernation soon thereafter early today, Sunday, Feb 23.
The abnormality occurred due to the “complicated lunar surface,” according to SASTIND.
Chinese space officials have not divulged the exact nature of the problems. And they have not released any details of the efforts to resolve the issues that “might cripple the vehicle.”
Since both Chinese Moon probes are solar powered, they must power down and enter a dormant mode during every two week long lunar night period when there is no sunlight to generate energy from their solar arrays. And no communications with Earth are possible.
The rover, nicknamed ‘Jade Rabbit’ remained stationary during the just concluded two week long lunar day time period, said SASTIND. It was unable to move due to the mechanical glitches.
“Yutu only carried out fixed point observations during its third lunar day.”
But it did complete some limited scientific observations. And fortunately the ground penetrating radar, panoramic and infrared imaging equipment are functioning normally.
The six wheel robot’s future was placed in jeopardy after it suffered the “mechanical anomaly” in late January 2014 and then awoke later than the scheduled time on Feb. 10, at the start of its 3rd Lunar Day.
To the teams enormous relief, a signal was finally detected.
“Yutu has come back to life!” said Pei Zhaoyu, the spokesperson for China’s lunar probe program, according to a Feb. 12 news report by the state owned Xinhua news agency.
“Experts are still working to verify the causes of its mechanical control abnormality.”
Since then, Chinese space engineers sought to troubleshoot the technical problems and were in a race against time to find a solution before the start of Lunar Night 3 this weekend.
“Experts had feared that it might never function again, but Yutu “woke up” on Feb. 12, two days behind schedule,” reported Xinhua.
Each lunar day and night lasts for alternating periods of 14 Earth days.
During each long night, the Moon’s temperatures plunge dramatically to below minus 180 Celsius, or minus 292 degrees Fahrenheit.
Both solar powered probes must enter hibernation mode during each lunar night to conserve energy and protect their science instruments and control mechanisms, computers and electronics.
“Scientists are still trying to find a fix for the abnormalities,” said CCTV, China’s official state television network.
So Yutu is now sleeping with the problems unresolved and no one knows what the future holds.
Hopefully Jade Rabbit awakes again in about two weeks time to see the start of Lunar Day 4.
The Chang’e-3 mothership lander and piggybacked Yutu surface rover soft landed on the Moon on Dec. 14, 2013 at Mare Imbrium (Sea of Rains) – marking China’s first successful spacecraft landings on an extraterrestrial body in history.
‘Jade Rabbit’ had departed the landing site forever, and was journeying southwards as the anomoly occurred – about six weeks into its planned 3 month long moon roving expedition to investigate the moon’s surface composition and natural resources.
The 140 kg Yutu robot is located some 100 m south of the lander.
The 1200 kg stationary lander is expected to return science data about the Moon and conduct telescopic observations of the Earth and celestial objects for at least one year.
Chang’e-3 and Yutu landed on a thick deposit of volcanic material.
China is only the 3rd country in the world to successfully soft land a spacecraft on Earth’s nearest neighbor after the United States and the Soviet Union.
Stay tuned here for Ken’s continuing Chang’e-3, Orion, Orbital Sciences, SpaceX, commercial space, LADEE, Mars and more planetary and human spaceflight news.
Who knew asteroids could be so beautiful and mesmerizing? In 2008, a group of astronomers led by Alex Parker did a study of the size distribution of asteroid families using data from the Sloan Digital Sky Survey. Asteroid families often have distinctive optical colors, the team said, and they were able to offer an improved way to separate out the family members into their colors. This resultant animation put together just this week by Parker shows the orbital motions of over 100,000 asteroids, with colors illustrating the compositional diversity and relative sizes of the asteroids.
“The compositional gradient of the asteroid belt is clearly visible,” says Parker, “with green Vesta-family members in the inner belt fading through the blue C-class asteroids in the outer belt, and the deep red Trojan swarms beyond that.”
All main-belt asteroids and Trojan asteroids with orbits known to high precision are shown in the video and the animation is rendered with a timestep of 3 days. Via Twitter, Parker said this animation took — from start to finish — 20 hours to render on 8 CPUs.
For reference, the average orbital distances of Mercury, Venus, Earth, Mars, and Jupiter are illustrated with rings.
NASA GODDARD SPACE FLIGHT CENTER, MARYLAND – Weather researchers and forecasters worldwide are gushing with excitement in the final days leading to blastoff of the powerful, new Global Precipitation Measurement (GPM) Core Observatory – built by NASA in a joint effort with Japan.
GPM is a next-generation satellite that will provide global, near real time observations of rain and snow from space and thereby open a new revolutionary era in global weather observing and climate science. Therefore it will have a direct impact on society and people’s daily lives worldwide.
The team is counting down to liftoff in less than 5 days, on Feb. 27 at 1:07 PM EST from the Tanegashima Space Center, on Tanegashima Island off southern Japan, atop the highly reliable Mitsubishi Heavy Industries H-IIA rocket.
The GPM launch to low Earth orbit was delayed by both natural and manmade disasters – namely the 2011 Fukushima earthquake in Japan as well as the ridiculous US government shutdown in Oct. 2013. That’s the same foolish shutdown that also delayed NASA’s new MAVEN Mars orbiter and numerous other US space & science projects.
The $933 Million mission is a joint venture between NASA and the Japan Aerospace Exploration Agency (JAXA), Japan’s space agency.
The mission will significantly advance our understanding of Earth’s water and energy cycles and improve forecasting of extreme weather events.
It is equipped with an advanced, higher resolution dual -frequency precipitation (DPR) radar instrument (Ku and Ka band) built by JAXA in Japan and the GPM microwave imager (GMI) built by Ball Aerospace in the US.
“The GPM satellite was built in house at NASA’s Goddard Space Flight Center in Maryland,” Art Azarbarzin, GPM project manager, told Universe Today during my exclusive up-close clean room inspection tour of the huge satellite as final processing was underway.
Shortly after my tour of GPM, the 3850 kilogram satellite was carefully packed up for shipment to the Japanese launch site.
“GPM will join a worldwide constellation of current and planned satellites,” Azarbarzin told me during an interview in the Goddard cleanroom with GPM.
And the imminent launch to augment the existing satellite constellation can’t come soon enough, he noted.
The GPM observatory will replace the aging NASA/JAXA Tropical Rainfall Measuring Mission (TRMM), satellite launched back in 1997.
“GPM is the direct follow-up to the currently orbiting TRMM satellite,” Azarbarzin explained.
“TRMM is reaching the end of its usable lifetime. GPM launches on February 27, 2014 and we hope it has some overlap with observations from TRMM.”
“The Global Precipitation Measurement (GPM) observatory will provide high resolution global measurements of rain and snow every 3 hours,” Dalia Kirschbaum, GPM research scientist, told me during an interview at Goddard.
It is vital to continuing the TRMM measurements and will help provide improved forecasts and advance warning of extreme super storms like Hurricane Sandy and Super Typhoon Haiyan, Azarbarzin and Kirschbaum explained.
Researchers will use the GPM measurements to study climate change, freshwater resources, floods and droughts, and hurricane formation and tracking.
“The water-cycle, so familiar to all school-age young scientists, is one of the most interesting, dynamic, and important elements in our studies of the Earth’s weather and climate,” said John Grunsfeld, associate administrator for NASA’s Science Mission Directorate in Washington, in a statement.
“GPM will provide scientists and forecasters critical information to help us understand and cope with future extreme weather events and fresh water resources.”
NASA TV will carry the launch live with commentary starting at 12 Noon EST on Feb. 27.
Stay tuned here for Ken’s continuing GPM reports and onsite coverage at NASA Goddard Space Flight Center in Maryland.
And watch for Ken’s continuing planetary and human spaceflight news about Curiosity, Opportunity, Chang’e-3, SpaceX, Orbital Sciences, LADEE, MAVEN, MOM, Mars, Orion and more.
I’ll admit it: I’m too young to remember 1984. I wish I did, however, because it was a banner year for the Manned Maneuvering Unit. NASA astronaut Dale Gardner, for example, used this jet backpack to retrieve malfunctioning satellites, as you can see above. (FYI, Gardner died Wednesday (Feb. 19) of a brain aneurysm at the age of 65.)
After three shuttle flights, however, NASA discontinued use of the backpack in space for several reasons — most famously, safety considerations following the shuttle Challenger explosion of 1986. But thirty years on, the problem of dead satellites is growing. There are now thousands of pieces whipping around our planet, occasionally causing collisions and generally causing headaches for people wanting to launch stuff into orbit safely.
Space agencies such as NASA and the European Space Agency have been working hard on reducing debris during launches, but there’s still stuff from decades before. And when a satellite goes dead, if it’s in the wrong orbit it could be circling up there for decades before burning up. How do you fix that?
Robotics has come a long way in 30 years, so space agencies are looking to use those instead to pick up derelict satellites since that would pose far less danger to astronauts. One example is the e.DeOrbit mission recently talked about by ESA, which would pick up debris in polar orbits of altitudes between 800 and 1,000 kilometers (about 500 to 620 miles).
The mission would use autonomous control and image sensors to get up close to the drifting satellite, and then capture it in some way. Several ideas are being considered, ESA added. A big enough net could easily nab the satellite, or perhaps one could clamp on using tentacles or grab it with a harpoon or robotic arm. Here’s a 2013 proposal with more information on e.DeOrbit. ESA noted there is a symposium coming up May 6 to discuss this in more detail.
e.DeOrbit is one of just several proposals to pick satellites up. A Swiss idea called CleanSpace One appears to use a sort of pincer claw to grab satellites for retrieval. The Phoenix program (proposed by Defense Advanced Research Projects Agency) would take useable parts off of broken satellites for use in new satellites, and in past years DARPA had some ideas to remove satellites from orbit as well. Another option is satellite refueling to make these machines useable again, a possibility that NASA, Canada and many others are taking seriously.
What do you think is the best solution? Leave your thoughts in the comments.