Posted on by Nancy Atkinson

Latest Phoenix Images: Ice or Salt?

The Phoenix lander team revealed the latest images from the mission at a press briefing on Friday. This first image shows an area dug by Phoenix’s scoop, which disclosed a bright surface just a few inches down, which may be ice. “There’s still some debate about the bright material,” said Phoenix Principle Investigator Peter Smith. “Not everyone is sure that this is ice. So there’s been some debate on our team, centering around that perhaps there’s a salt layer just under the soil that also would be bright. Everyone does believe there’s ice under the surface, and whether this is ice or not is the question. The other question is, is this thick ice that goes down deep beneath the surface, or is this a thin layer and we’ll be able to scrape through? So being able to scrape with our scoop is a high priority for us.”


This pair of images taken by the Optical Microscope on NASA’s Phoenix Mars Lander offers a side-by-side comparison of an airfall dust sample collected on a substrate exposed during landing (left) and a soil sample scooped up from the surface of the ground beside the lander. In both cases the sample is collected on a silicone substrate, which provides a sticky surface holding sample particles for observation by the microscope.

Similar fine particles at the resolution limit of the microscope are seen in both samples, indicating that the soil has formed from settling of dust.

The microscope took the image on the left during Phoenix’s Sol 9 (June 3, 2008), or the ninth Martian day after landing. It took the image on the right during Sol 17 (June 11, 2008).

The scale bar is 1 millimeter (0.04 inch).


This is the latest color image of Phoenix, its surroundings and the scoop with soil.


While we can’t look inside the Thermal and Evolved Gas Analyzer (TEGA) oven which will “bake” the Martian soil to test the type of gases that are released, we can see that some of the soil has gone into TEGA. “We were finally successful and some of the material has slid down over the screen” said Smith, “sort of like material going over a cheese grater, and some of the material has slid down and filled the oven. We sent the commands for the first operation of TEGA last night, but we don’t have our data back yet, so we can’t report on any results. That will be coming later next week. So this is a very exciting time for us. We find the soil is very clumpy, it’s sticky, it’s an unusual soil not at all like the types of soils we used in our tests, which worked just fine with all the instruments. So we’ve developed another method of collecting samples, which is to tilt the scoop and vibrate it, and so it shakes down a small amount of material onto the instruments.”


And finally, here’s the latest weather report for Mars, on the 17th sol of Phoenix’s stay on Mars.

Sources: Phoenix News, NASA TV

Posted on by Fraser Cain

How Long is a Year on Earth?

The eccentricity in Mars' orbit means that it is . Credit: NASA

A year on Earth is obviously 1 year long, since it’s the standard of measurement. But we can break it down further.

A year is 365.24 days. Or 8,765 hours, or 526,000 minutes, or 31.6 million seconds.

The tricky one is the number of days. Because the earth year doesn’t work out to exactly 365 days, we have the leap year. If we didn’t, days in the calendar wouldn’t match up with the position of the Earth in its orbit. Eventually, the months would flip around, and the northern hemisphere would have summer in January, and vice versa.

To fix this, we put on extra days in some years, called leap years. In those leap years, a year lasts 366 days, and not the usual 365. This gets tacked onto the end of February. Normally, February only has 28 days, but in leap years, it has 29 days.

When to you have leap years? It’s actually pretty complicated.

The basic rule is that you have a leap year if you can divide the year by 4. So 2004, 2008, etc. But years divisible by 100 are not leap years. So 1800, 1900 aren’t leap years. Unless they’re divisible by 400. So 1600 and 2000 are leap years. By following this algorithm, you can have an Earth orbit that lasts 365.24 days.

With the current system, it’s not actually perfect. There’s an extra 0.000125 days being accumulated. Over course of 8,000 years, the calendar will lose a single day.

Here’s an article about how astronomers might use cosmic rays to measure time on Earth.

And here is more information on how to calculate leap years from timeanddate.com.

We did an episode of Astronomy Cast just on the Earth. Give it a listen, Episode 51: Earth.

Posted on by Nancy Atkinson

Thinking About Time Before the Big Bang

What happened before the Big Bang? The conventional answer to that question is usually, “There is no such thing as ‘before the Big Bang.'” That’s the event that started it all. But the right answer, says physicist Sean Carroll, is, “We just don’t know.” Carroll, as well as many other physicists and cosmologists have begun to consider the possibility of time before the Big Bang, as well as alternative theories of how our universe came to be. Carroll discussed this type of “speculative research” during a talk at the American Astronomical Society Meeting last week in St. Louis, Missouri.

“This is an interesting time to be a cosmologist,” Carroll said. “We are both blessed and cursed. It’s a golden age, but the problem is that the model we have of the universe makes no sense.”

First, there’s an inventory problem, where 95% of the universe is unaccounted for. Cosmologists seemingly have solved that problem by concocting dark matter and dark energy. But because we have “created” matter to fit the data doesn’t mean we understand the nature of the universe.

Another big surprise about our universe comes from actual data from the WMAP (Wilkinson Microwave Anisotropy Probe) spacecraft which has been studying the Cosmic Microwave Background (CMB) the “echo” of the Big Bang.

“The WMAP snapshot of how the early universe looked shows it to be hot, dense and smooth [low entropy] over a wide region of space,” said Carroll. “We don’t understand why that is the case. That’s an even bigger surprise than the inventory problem. Our universe just doesn’t look natural.” Carroll said states of low-entropy are rare, plus of all the possible initial conditions that could have evolved into a universe like ours, the overwhelming majority have much higher entropy, not lower.

But the single most surprising phenomenon about the universe, said Carroll, is that things change. And it all happens in a consistent direction from past to future, throughout the universe.

“It’s called the arrow of time,” said Carroll. This arrow of time comes from the second law of thermodynamics, which invokes entropy. The law states that invariably, closed systems move from order to disorder over time. This law is fundamental to physics and astronomy.

One of the big questions about the initial conditions of the universe is why did entropy start out so low? “And low entropy near the Big Bang is responsible for everything about the arrow of time” said Carroll. “Life and death, memory, the flow of time.” Events happen in order and can’t be reversed.

“Every time you break an egg or spill a glass of water you’re doing observational cosmology,” Carroll said.

Therefore, in order to answer our questions about the universe and the arrow of time, we might need to consider what happened before the Big Bang.

Carroll insisted these are important issues to think about. “This is not just recreational theology,” he said. “We want a story of the universe that makes sense. When we have things that seem surprising, we look for an underlying mechanism that makes what was a puzzle understandable. The low entropy universe is clue to something and we should work to find it.”

Right now we don’t have a good model of the universe, and current theories don’t answer the questions. Classical general relativity predicts the universe began with a singularity, but it can’t prove anything until after the Big Bang.

Inflation theory, which proposes a period of extremely rapid (exponential) expansion of the universe during its first few moments, is no help, Carroll said. “It just makes the entropy problem worse. Inflation requires a theory of initial conditions.”

There are other models out there, too, but Carroll proposed, and seemed to favor the idea of multi-universes that keep creating “baby” universes. “Our observable universe might not be the whole story,” he said. “If we are part of a bigger multiverse, there is no maximal-entropy equilibrium state and entropy is produced via creation of universes like our own.”

Carroll also discussed new research he and a team of physicists have done, looking at, again, results from WMAP. Carroll and his team say the data shows the universe is “lopsided.”

Measurements from WMAP show that the fluctuations in the microwave background are about 10% stronger on one side of the sky than on the other.

An explanation for this “heavy-on-one-side universe” would be if these fluctuations represented a structure left over from the universe that produced our universe.

Carroll said all of this would be helped by a better understanding of quantum gravity. “Quantum fluctuations can produce new universes. If thermal fluctuation in a quiet space can lead to baby universes, they would have their own entropy and could go on creating universes.”

Granted, — and Carroll stressed this point — any research on these topics is generally considered speculation at this time. “None of this is firmly established stuff,” he said. “I would bet even money that this is wrong. But hopefully I’ll be able to come back in 10 years and tell you that we’ve figured it all out.”

Admittedly, as writer, trying to encapsulate Carroll’s talk and ideas into a short article surely doesn’t do them justice. Check out Carroll’s take on these notions and more at his blog, Cosmic Variance. Also, read a great summary of Carroll’s talk, written by Chris Lintott for the BBC. I’ve been mulling over Carroll’s talk for more than a week now, and contemplating the beginnings of time — and even that there might be time before time — has made for an interesting and captivating week. Whether that time has brought me forward or backward in my understanding remains to be seen!

Posted on by Nancy Atkinson

Wilkins Ice Shelf Continues Break-up, Even During Winter

Satellite images reveal the Wilkins Ice Shelf in Antarctica has experienced further break-up with an area of about 160 square kilometers breaking off during May 30 -31, 2008. ESA’s Envisat satellite captured the event. This is the first ever-documented episode to occur during the Antarctic winter. The animation here, comprised of images acquired by Envisat’s Advanced Synthetic Aperture Radar (ASAR) between May 30 and June 9, highlights the rapidly dwindling strip of ice that is protecting thousands of kilometers of the ice shelf from further break-up.

Wilkins Ice Shelf, a broad plate of floating ice south of South America on the Antarctic Peninsula, is connected to two islands, Charcot and Latady. In February 2008, an area of about 400 square km broke off from the ice shelf, narrowing the connection down to a 6 km strip; this latest event in May has further reduced the strip to just 2.7 km.

According to Dr. Matthias Braun from the Center for Remote Sensing of Land Surfaces, Bonn University, and Dr. Angelika Humbert from the Institute of Geophysics, Münster University, who have been investigating the dynamics of Wilkins Ice Shelf for months, this break-up has not yet finished.

“The remaining plate has an arched fracture at its narrowest position, making it very likely that the connection will break completely in the coming days,” Braun and Humbert said.
Long-term satellite monitoring over Antarctica is important because it provides authoritative evidence of trends and allows scientists to make predictions. Ice shelves on the Antarctic Peninsula are important indicators for on-going climate change because they are sandwiched by extraordinarily raising surface air temperatures and a warming ocean.

The Antarctic Peninsula has experienced extraordinary warming in the past 50 years of 2.5°C, Braun and Humbert explained. In the past 20 years, seven ice shelves along the peninsula have retreated or disintegrated, including the most spectacular break-up of the Larsen B Ice Shelf in 2002, which Envisat captured within days of its launch.

News Source: ESA

Posted on by Nancy Atkinson

Doritos In Space

I’m all for the commercial use of space, but this might be a bit overboard. Back in March of this year, Ian reported on a fund raising scheme to help the United Kingdom’s physics and astronomy money woes. The scheme involved soliciting commercial companies to pay for advertising being beamed into space, supposedly directed towards potential extra terrestrial life. The manufacturer of Doritos snack chips stepped up, donating an undisclosed sum in exchange for transmitting their ad. But the Doritos people decided to turn the advertisement into a contest, and created the Doritos Broadcast Project, which invited the UK public to create a 30 second video clip that could be beamed out to the universe offering a snap shot of life on earth to anyone ‘out there’. According to a poll, 61% of the UK public believe this is just the start of communication with ET life and that we will enter into regular communication with an alien species at some stage in the future. See the winning commercial:

The winning space-ad entitled ‘Tribe’ was voted for by the British public and directed by 25-year-old Matt Bowron. It will officially be entered into the Guinness Book of Records and will be aired on the more conventional medium of television in the UK on Sunday, June 15th.

Does this really offer a “snapshot of life on Earth?” Is this the impression of ourselves we’d like to give to extraterrestrials?

The message is being pulsed out over a six-hour period from high-powered radars at the EISCAT European space station in the Arctic Circle. The University of Leicester has also been involved in the project from its inception.

EISCAT Director, Professor Tony van Eyken who will oversee the transmission said: “The signal is directed at a solar system just 42 light years away from Earth, in the ‘Ursa Major’ or Great Bear Constellation. Its star is very similar to our Sun and hosts a habitable zone that could harbor small life supporting planets similar to ours.”

Peter Charles, Head of the Doritos Broadcast Project said: “We are constantly looking to push the boundaries of advertising and this will go further than any brand has gone before. By broadcasting the winning ad to the Universe, Doritos is delivering a world first and Matt Bowron, the winner, will go down in advertising folklore. We also shouldn’t be too surprised if the first aliens start arriving on planet Earth immediately demanding a bag of Doritos.”

Wow.

Dr Nigel Bannister thinks the idea might stimulate extra public interest. “The idea of transmitting an ad into space is somewhat controversial but still of scientific interest,” he said.

“This could be a test for future very long range communications and it gives us an opportunity to tell the Universe we are here (in case someone out there is listening – like reversal of the SETI programme!).

“There could also be potential commercial interest in enterprises like this. Imagine one day that companies on Earth might wish to advertise to other planetary colonies within our solar system -for example if man ever moves to colonise Mars!”

Source: Space Daily

Posted on by Nancy Atkinson

Crew Sees Object Float Away From Shuttle (Update)

Update: After a quick but thorough analysis of photos and video of the object and the “protuberance” on the shuttle tail fin, NASA officials say neither should pose any problem for the shuttle landing on Saturday. The object floating away was determined to be one of three thermal clips that are inside the rudder speed brake on the tail fin. They are normally fixed to the back end of the rudder, and NASA astronaut Terry Virts said it is common for these clips to be missing following a mission. Image analysts compared previous images of the clips to telephoto images taken by the crew today to determine it was one of the clips. The “protuberance” on the tail fin is considered to be “nominal” or normal, and was just a separation in the tail’s thermal cover that was enhanced by the lighting from the sun at that time, and does not pose a problem.
This morning around 6:30 am EDT, the crew of STS-124 activated the shuttle’s auxiliary power units to test the shuttle’s re-entry systems for Saturday’s scheduled landing. Everything checked out fine, but shortly afterward the crew reported seeing an object floating away from the shuttle. The crew was able to capture video of the object as it tumbled away. “We observed an object depart aft of the starboard wing,” Commander Mark Kelly said. “Looked like, and obviously it’s hard to tell dimensions and size looking out the aft windows, but it looked like it might have been a foot to a foot and a half in width. And we’ve got a pretty reasonable image of it.”

Additionally, the crew also noticed a protuberance on the shuttle’s tail fin, thought to be a small piece of thermal insulation. NASA TV reported that NASA officials are not currently overly concerned about the protuberance, but additional images are being taken by the crew and downloaded for review by experts in Houston.

NASA TV commentator Rob Navias it is not uncommon for objects to become dislodged from the payload bay or for ice from the engine bell to become dislodged after the shuttle has unusual movements, such as when auxiliary power units are activated or tested. However, the object is large enough that further review of the incident is warranted. There is no concern about the object re-contacting the shuttle, but it is being tracked from the ground.

NASA is also studying video plus digital stills of the area on the shuttle’s tail fin, at the intersection of the lower and top sections of the rudder that meet to form the speed brake, used during landing. All the aero surfaces of the rudder and speed brake were tested this morning, with five movements in either direction, and no unusual data was detected. NASA reports that all the landing systems appear to be in good shape to support entry and landing.

The area in question on the tail fin is covered with a reusable thermal protection system and it does have a thermal barrier seal. That seems to be where the slight “bump” as the crew called it, or protuberance is.

This morning Kelly, Pilot Ken Ham and flight engineer Ron Garan are honing in on their piloting skills by conducting a computer simulation of landing the shuttle.

There will be media interviews with the shuttle crew at about 11:50 this morning, where details of the object and protuberance might be discussed. Look for updates here.

News Sources: NASA TV, Spaceflightnow.com

Posted on by Nancy Atkinson

Ulysses Mission to End After 17 Years

For more than 17 years the Ulysses spacecraft studied the sun, pioneering solar science and defining our knowledge of the sun’s heliosphere. But on July 1, the mission will end. The spacecraft has been slowly “dying” due a dwindling power supply which can no longer keep the spacecraft warm enough. But Ulysses lasted almost four times its expected lifespan and has forever changed the way scientists view the sun and its effect on the surrounding space.

Ulysses ends its career after revealing that the magnetic field emanating from the sun’s poles is much weaker than previously observed. This could mean the upcoming solar maximum period will be less intense than in recent history.

“Over almost two decades of science observations by Ulysses, we have learned a lot more than we expected about our star and the way it interacts with the space surrounding it,” said Richard Marsden, Ulysses project scientist and mission manager for the European Space Agency (ESA). “Solar missions have appeared in recent years, but Ulysses is still unique today. Its special point of view over the sun’s poles never has been covered by any other mission.”

Ulysses is in a six-year orbit around the Sun. Its long orbital path carries it out to Jupiter’s orbit and back again. The further it ventures from the Sun, the colder the spacecraft becomes. Once it drops to 2ºC, the spacecraft’s hydrazine fuel will freeze.

This has not been a problem in the past because Ulysses carries heaters to maintain a workable on-board temperature. The spacecraft is powered by the decay of a radioactive isotope and over the 17-plus years, the power it has been supplying has been steadily dropping. Now, the spacecraft no longer has enough power to run all of its communications, heating and scientific equipment simultaneously.

The spacecraft and its suite of 10 instruments had to be highly sensitive, yet robust enough to withstand some of the most extreme conditions in the solar system, including intense radiation while passing by the giant planet Jupiter’s north pole.

Ulysses was the first mission to survey the environment in space above and below the poles of the sun in the four dimensions of space and time. It showed the sun’s magnetic field is carried into the solar system in a more complicated manner than previously believed. Particles expelled by the sun from low latitudes can climb to high latitudes and vice versa, sometimes unexpectedly finding their way out to the planets. Ulysses also studied dust flowing into our solar system from deep space, and showed it was 30 times more abundant than astronomers suspected. In addition, the spacecraft detected helium atoms from deep space and confirmed the universe does not contain enough matter to eventually halt its expansion.

Ulysses has traveled over 8.6 billion kilometers (5.4 billion miles) during its lifetime.

“Ulysses has been a challenging mission since launch,” said Ed Massey, Ulysses project manager at JPL. “Its success required the cooperation and intellect of engineers and scientists from around the world.”

Ulysses has been a joint mission between NASA and ESA.

“When the last bits of data finally arrive, it surely will be tough to say goodbye,” said Nigel Angold, ESA’s Ulysses mission operations manager. “But any sadness I might feel will pale in comparison to the pride of working on such a magnificent mission. Although operations will be ending, scientific discoveries from Ulysses data will continue for years to come.”

News Source: JPL Press Release

Posted on by Fraser Cain

Carnival of Space #58



This week, the Carnival returns to its home port for a week. That’s right, we’re hosting it here at Universe Today. Let’s get right to this week’s entries.

At Mang Bat’s Page, David Gamey thinks budding astronomers should never start with a telescope – invest in a good pair of binoculars instead.

Over at Colony Worlds, Darnell Clayton considers how future colonists will want to grow bamboo to get instant forests.

At Dynamics of Cats, Steinn Sigurðsson analyzes NASA’s newly announced shortlist of Small Explorer missions.

As Phoenix settles down on Mars to begin its third week of work, Stuart Atkinson wonders what could be responsible for the problems with getting samples of precious martian dust into the waiting TEGA ovens, and comes up with two – surprising – possible explanations…

Martian Chronicles also looks at the very clumpy soil that Phoenix tried, and failed, to process through its shake and bake method.

Catholic Sensibility begins a series on Solar System satellites. First up, the Galilean Moons of Jupiter.

Pluto gets to raise its head high again, with the newly designated Plutoids. Astroprof has the details about the IAU’s new decision.

Irene Klotz over at Discovery News thinks the US should steal the Soyuz. Well, not steal it exactly.

The space show airs the audio of the first ever Space Cynics’ Roundtable, and all sacred cows are fair game, so to speak…

At A Babe in the Universe, you can get a look at the newly announced probe that will fly right through the hot corona of the Sun.

Next Big Future has a list of the top 10 upcoming developments in space technology that will vastly improve the exploration of space.

At Bad Astronomy, Phil talks about an experiment that will test quantum mechanics on the International Space Station.

Centauri Dreams reports on plans to build a light tower to memorialize the victims of hurricane Katrina, and thinks about how this could apply to solar sail technology.

Ed Minchau has a space video of the week. This time, a summary of the major events of mission STS-124.

How many astronomers does it take to screw in a light bulb?

The Lunar and Planetary Institute has some new 35 mm images taken during the Apollo 17 mission.

David Portree has a piece about model rocketry on Mars.

Our very own Ian O’Neill has an article entitled “The Case of the Supermassive Black Hole, the Infrared Object and Perceived Accuracy of Science”

Clark Lindsey at Hobbyspace announces an upcoming event for the X-Prize Lunar Lander Challenge.

Music of the Spheres discusses cycling to Mars. No, not on a bicycle, but on a space station that travels back and forth from Earth to Mars.

At Starts with a Bang, Ethan Siegel has completed the 3rd part of a series about the natural history of the Universe. Here are all 3 parts. Part 1 – Part 2 – Part 3

At Visual Astronomy, Sean Welton explains how the Aurora Borealis works.

And last, but not least, Universe Today’s Nancy Atkinson shows what the new Constellation spacesuits might look like.

Phew, that’s all of them.

And if you’re interested in looking back, here’s an archive to all the past carnivals of space. If you’ve got a space-related blog, you should really join the carnival. Just email an entry to [email protected], and the next host will link to it. It will help get awareness out there about your writing, help you meet others in the space community – and community is what blogging is all about. And if you really want to help out, let me know if you can be a host, and I’ll schedule you into the calendar.

Finally, if you run a space-related blog, please post a link to the Carnival of Space. Help us get the word out.

Posted on by Fraser Cain

What is the Driest Place on Earth?

Dry Valleys. Image credit: NASA

The driest place on Earth is in Antarctica in an area called the Dry Valleys, which have seen no rain for nearly 2 million years. There is absolutely no precipitation in this region and it makes up a 4800 square kilometer region of almost no water, ice or snow. Water features include Lake Vida, Lake Vanda, Lake Bonney and the Onyx River. There is no net gain of water. The reason why this region receives no rain is due to Katabatic winds, winds from the mountains that are so heavy with moisture that gravity pulls them down and away from the Valleys.

One feature of note is Lake Bonney, a saline lake situated in the Dry Valleys. It is permanently covered with 3 to 5 meters of ice. Scientists have found mummified bodies of seals around the lake. Lake Vanda, also in the region, is 3 times saltier than the ocean. Temperatures at the bottom of this lake are as warm as 25 degrees Celsius.

The next driest place in the world measured by the amount of precipitation that falls is the Atacama Desert in Chile and Peru. There are no glaciers that are feeding water to this area; and thus, very little life can survive. Some weather stations in this region have received no rain for years, while another station reports an average of one millimeter per year.

Posted on by Fraser Cain

Lowest Point on Earth

The Dead Sea from space. Image credit: NASA

The lowest point on land is the Dead Sea that borders Israel, the West Bank and Jordan. It’s 420 meters below sea level.

The Dead Sea sits on top of the Dead Sea Rift, a tectonic fault line between the Arabian and the African plates. The movement of these plates causes the Dead Sea to sink about one meter per year! The Dead Sea used to be connected to the Mediterranean Ocean, but over a geologic time scale, it became cut off and evaporation concentrated the salt in the water so that today, the Dead Sea is 30 to 31 percent mineral salts. It has the highest level of salinity of any body of water in the world. Just a side note, I’ve had a chance to swim in the dead sea, and it’s one of the strangest experiences I’ve ever had.

The lowest point on land in the Western Hemisphere is Death Valley in California at 86 meters below sea level.

The lowest point on the Earth’s crust is the Mariana’s Trench in the North Pacific Ocean. It is 11 kilometers deep. Like many of Earth’s extremes, the Mariana’s Trench is caused by the Pacific tectonic plate subducting beneath the Philippine plate; this means that the Pacific Plate is sliding underneath the Philippine plate. The point where the Philippine plate overlaps is Mariana’s Trench.