Images From The STS-124 Mission

The crew of the STS-124 mission has been busy installing equipment on the International Space Station, fixing a toilet, and trying out the latest robotic arm that’s part of the shiny new Kibo module. The image above shows some of the new additions to the station, which just keeps growing in size with every mission. The mass of modules shown are: the Japanese Pressurized Module (left), the Japanese Logistics Module (top center), the Harmony node (center), the Destiny laboratory (right) of the ISS, and the forward section of Space Shuttle Discovery that is docked to the station.


Astronauts Mike Fossum (left) and Ron Garan, during the second EVA for the mission. The two astronauts installed television cameras on the Kibo Japanese Pressurized Module (JPM) that will aid in the Kibo robotic arm operations, they also removed thermal covers from the Kibo robotic arm, prepared an upper JPM docking port for flight day seven’s attachment of the Kibo logistics module, readied a spare nitrogen tank assembly for its installation during the third spacewalk, retrieved a failed television camera from the Port 1 truss, and inspected the port Solar Alpha Rotary Joint (SARJ). In looking at the SARJ, Fossum found grease streaks and a small amount of a dust-like material. In the third spacewalk, coming up on Sunday, the astronauts will take samples of the materials for further testing. They’ll also continue outfitting and activating the Kibo module.


Inside Kibo: STS 124 Commander Mark Kelly (right) and pilot Ken Ham add a rack inside the recently installed Kibo Pressurized Module.


This is a great image of Space Shuttle Discovery with Earth’s limb in the background. Also visible are parts of the shuttle: the Remote Manipulator System (RMS), the docking mechanism, vertical stabilizer and orbital maneuvering system (OMS) pods. This was taken on flight day two, before the shuttle docked with the space station.

Image Source: NASA Human Spaceflight Gallery

Temperature of Mars

Temperature of Mars
What is the Temperature of Mars? Image credit: NASA/JPL

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Mars is farther from the Sun than the Earth, so, as you would expect, the temperature of Mars is colder. For the most part it is very cold on Mars. The only exception is during the summer days close to or at the equator. Even at the equator, the night time temperatures fall well below zero. On those summer days, it can be around 20 degrees Celsius then plummet to -90 C at night.

Mars follows a highly elliptical orbit, so temperatures vary quite a bit as the planet travels around the Sun. Since Mars has an axial tilt similar to Earth’s(25.19 for Mars and 26.27 for Earth), the planet has seasons as well. Add to that a thin atmosphere and you can see why the planet is unable to retain heat. The Martian atmosphere is over 96% carbon dioxide. If the planet had an atmosphere to retain heat, the carbon dioxide would cause a greenhouse effect that would heat Mars to jungle like temperatures.

Scientist know the current temperature of Mars, but what about the past. Rovers and orbiters have returned images that indicate erosion patterns that can only be caused by liquid water. That would seem to indicate that Mars was once much warmer and wetter. Here on Earth, those features would have been covered in soil after a few million years. So, was Mars warmer just a few million years ago? No, Mars has been a frigid planet for at least 3 billion years and some scientist believe it has been frozen for 4 billion years. The erosion features have not disappeared because there is no current liquid water or plate tectonics to change the landscape. What wind there is, does not seem strong enough to further erode the surface.

Tracking the presence of warmer weather and liquid water on Mars is important for a few reasons. One is that liquid water is essential for the evolution of life as we know it. Some scientists still hold out hope that there is microbial life deep beneath the surface where it is warmer and water may exist. Secondly, if humans are to ever explore the planet, they would need a water source. A human mission would take nearly two years to complete and storage space would be limited. Water ice may be melted upon arrival then purified, but finding a supply of liquid water would be even more expedient.

The temperature of Mars is a minor obstacle to early human exploration, while water is more pressing. Current spacesuits would survive the surface temperatures. Now, all we have to do is find a way to get there and back without having to spend two years in a cramped modern spacecraft.

Here’s news that Mars has probably been cold for billions of years, and more information about Mars, and just how cold it gets.

Here’s an overview of temperatures on Mars. Mars News has more info on Mars.

Finally, if you’d like to learn more about Mars in general, we have done several podcast episodes about the Red Planet at Astronomy Cast. Episode 52: Mars, and Episode 91: The Search for Water on Mars.

Sources:
http://www-k12.atmos.washington.edu/k12/resources/mars_data-information/temperature_overview.html
http://www.nasa.gov/multimedia/imagegallery/image_feature_1160.html
http://solarsystem.nasa.gov/planets/profile.cfm?Object=Mars&Display=Facts

Possible Solution to Solar Flare Damage to Satellites

Powerful solar flares can cause charge build-up on satellites (NASA)

When a solar flare blasts energetic particles and magnetic flux at Earth, our satellites are on the front line. As coronal mass ejections (CMEs) interact with the Earth’s magnetosphere, there is a huge injection of energetic electrons into the Earth’s radiation belts. This can have dire consequences for the satellites that we depend on for communications around the globe. All is not lost however. An international team of scientists have stumbled upon a possible, innovative solution to discharge these troublesome electrons into the atmosphere: bathe the skies in radio waves.

The magnetosphere (protective layers of geomagnetic field lines) traps energetic particles in a volume of space known as the Van Allen belt. Our satellites are constantly travelling through this high radiation environment. Most satellites are shielded from all but the worst the Van Allen belt can throw at them, but should the Sun send a high concentration of energetic particles at the Earth after a solar flare, the environment in the magnetosphere becomes a very dangerous place. Should the delicate circuitry on board the spacecraft be hit by energetic particles (a situation that possibly caused Mars Odyssey to be switched to “safe-mode”), the satellite could be irreversibly damaged.

Now, a chance discovery by French and New Zealand scientists indicate that magnetospheric electrons can be discharged into the atmosphere by using ground-based radio transmitters. This finding comes from a new paper to be published in the journal Geophysical Research Letters. Rory Gamble, a PhD student of the University of Otago in Dunedin, New Zealand, and his colleagues were analysing the data from DEMETER (Detection of Electro-Magnetic Emissions Transmitted from Earthquake Regions), a satellite sensitive to radiation changes in the magnetosphere. As the satellite passed over a military transmitter in Western Australia, they noticed that magnetospheric electrons were discharged into the atmosphere, thereby removing them from the magnetosphere.

We were able to determine that this transmitter has a direct effect on the electrons in the radiation belts [in the magnetosphere], it caused those electrons to crash into the top of the atmosphere and be removed from the radiation belts.” – Rory Gamble

This finding is a very exciting development for the human-influenced manipulation of the levels of radiation in the magnetosphere. During periods of high solar activity, when energetic electrons are expected to populate the radiation belts in higher densities, there could be a system in place to bathe the sky in radio waves, allowing safer passage for satellites. This phenomenon has been known to exist when transmitting radio waves in space, but this is the first example of electron discharge from a ground-based transmitter.

Source: ABC

Phoenix Suffers Unknown Problem with Sample Analysis Oven

Mars dirt doesn't make it to the oven for testing (NASA/UA)

The first sample for scientific analysis dug from the surface of the Mars has failed to make it to the onboard oven used to test for organic compounds and water. Mission scientists have been overviewing a picture taken by the lander after Phoenix’s 8-foot long robotic arm dropped the sample on-target, but a sensor inside the chamber has reported seeing nothing falling into the oven. The regolith sample can be clearly seen scattered over the oven doors (pictured), and the vibration plate appears to be functioning. Mission control is currently trying to understand what went wrong, so sample analysis has been postponed, possibly for a few days…

Everything was looking fine as the robotic arm reached out and dug into the Martian top layer of regolith on Sol 11 (June 5th) of the Phoenix Mars Mission. The Martian dirt was excavated from a little patch known as “Baby Bear” and then lifted above the open doors of the Thermal and Evolved-Gas Analyzer (TEGA – a hi-tech oven used to bake the samples and analyze the gases emitted). The robotic arm then released the sample on to the vibrator above the open TEGA hatch. The vibrating plate, used to shake the sample into the oven chamber, was registered as working as it should. It all seemed fine, even the picture taken of the dropped regolith on the top deck of Phoenix fell in the right place. Unfortunately, the electronic “eye” inside the chamber did not detect any falling grains of dirt.

University of Arizona mission scientists are understandably concerned about this complication. “We think everything is working correctly, although we don’t really know for sure,” William Boynton, UA Tucson researcher who is overlooking the oven experiments, said in a news briefing today (Saturday). “We’re a little bit concerned about this but we have some other things to check out.

If the regolith was dropped in the right place, and the vibrating plate appears to be working as it should, why have no particles been registered as entering the open chamber? The problem could lie in the screen at the top of the TEGA. The screen will only allow small particles into the chamber for analysis. If the regolith is too compacted, or is composed of larger-than-expected particles, none may be able to enter the oven. On the other hand, the instrument readings from the vibrator are in fact wrong, meaning it is not working and particles are not being fed into the chamber.

But do not be alarmed. If the oven is broken, Phoenix has come prepared. This oven is one of eight on board, so whilst scientists try to understand the problem, at least they know they have another seven ovens to take over the mission’s primary objectives. In the mean time, mission control will send commands to the lander to analyse the area it excavated with its robotic arm and cameras.

Source: Associated Press

SkyWatcher Alert: Moon, Mars, Saturn and More…

Greetings, fellow SkyWatchers! As the summer heats up for the northern hemisphere and the winter cools down the southern, we’re in for interesting celestial scenery over the next few days. No special equipment is needed – only your eyes and the knowledge of knowing where and when to look….

On the universal date of Sunday, June 8, 2008 the Red Planet – Mars – and the Moon will make a splendid showing for all. As skies darken, look for impressive pair along the western ecliptic. For most of us, Mars and the earthshine Moon will only be separated by about a degree, but for lucky observers in New Zealand, this will be an occultation event! (For specific details on times and areas, please check IOTA information.) Get out your binoculars and have a look. Even the youngest SkyWatcher will easily be able to find Mars!

While the Phoenix mission is still making big news, use this opportunity to do some public astronomy outreach. Point the pair out in the sky to someone and tell what you know. Around 40 years has elapsed since humankind has first visited one – and then the other. How did our original expeditions to the Moon lead scientists to develop ever better instruments for remote study? How has our exploratory spacecraft evolved?

If you think that’s cool… Then stay tuned for Monday, June 9, 2008 when the Moon, Saturn and Regulus team up in the night sky. To the unaided eye, the trio will make a lovely triangle with the Ringed Planet and the Little King situated to the north of Selene. Again, it’s a great time to do some public outreach! Point a telescope Saturn’s way. Titan – Saturn’s largest moon – is visibly bright and can be seen in even small telescopes. Explain how our original fly-bys and landings on our own Moon led us on to explore a moon on a distant world! What did we find on Titan? How can it compare to what we discovered on the Moon and Mars?

Don’t forget Regulus, either. The light you see from it on this night would have left roughly in 1931 – long before expeditions to the Moon, Saturn and Mars were even dreamed of. At about three and a half times more massive than our own Sol, Regulus is one hot customer when it comes to spin rate. Revolving completely on its axis in a little less than 16 hours, oblate Regulus would fly apart if it were moving any faster! Even though it’s been around for a few million years, Regulus isn’t alone, either. The “Little King” is a multiple star system composed of a hot, bright, bluish-white star with a pair of small, faint companions.

Even if you only use your eyes, the next few days are a great opportunity to share what you love and know with others… Enjoy!

Moon Occulting Mars Image – Credit: Ron Dantowitz, Clay Center Observatory at Dexter and Southfield Schools. Saturn and Titan – Credit: Casinni/NASA. Regulus vs. the Sun – Wenjin Huang

Mars Tilt

Mars Ice Age.
Mars Ice Age.

Of all the features of Mars, its axial tilt is most similar to Earth. Mars’ tilt is 25 degrees, just a fraction away from the Earth’s 23.5 degrees. And because of this tilt, Mars has seasons, just like the Earth. Of course, since Mars takes twice as long as Earth to orbit the Sun, the seasons are twice as long.

Mars also has a very elliptical orbit. Because of this, the difference between its closest and most distant point along its orbit vary by 19%. This extreme difference makes the planet’s southern winters long and extreme. The northern winters aren’t as long or cold.

Astronomers know that the current tilt of Mars’ axis is just a fluke. Unlike Earth, the planet’s tilt has changed dramatically over long periods of time. In fact, astronomers think that the wobble in the tilt might help explain why vast underground reservoirs of water ice have been found at mid-latitudes, and not just around the planet’s poles. It’s possible that in the distant past, Mars was tilted at a much more extreme angle, and the ice caps were able to grow across the planet. When the tilt was less extreme, the ice remained, and was covered by a layer of dust.

Researchers have developed a model that accounts for the advance and retreat of the subsurface Martian ice sheets over 40 ice ages and 5 million years.

Here’s an article that explains how scientists track the Martian equator in the past. And the lopsided ancient oceans on Mars are explained by its tilt in the past.

Here’s some information about the tilt and seasons on Mars from MSSS. And the Wikipedia article about timekeeping on Mars.

Finally, if you’d like to learn more about Mars in general, we have done several podcast episodes about the Red Planet at Astronomy Cast. Episode 52: Mars, and Episode 91: The Search for Water on Mars.

Mars Dust Storms



Mars dust storms are much different than the dust devils that many people have seen in images sent back from the planet. On Mars a dust storm can develop in a matter of hours and envelope the entire planet within a few days. After developing, it can take weeks for a dust storm on Mars to completely expend itself. Scientists are still trying to determine why the storms become so large and last so long.

All Mars dust storms are powered by sunshine. Solar heating warms the Martian atmosphere and causes the air to move, lifting dust off the ground. The chance for storms is increased when there are great temperature variations like those seen at the equator during the Martian summer. Because the planet’s atmosphere is only about 1% as dense as Earth’s only the smallest dust grains hang in the air.

Surprisingly, many of the dust storms on the planet originate from one impact basin. Hellas Basin is the deepest impact crater in the Solar System. It was formed more than three billion years ago during the Late Bombardment Period when a very large asteroid hit the surface of Mars. The temperatures at the bottom of the crater can be 10 degrees warmer than on the surface and the crater is deeply filled with dust. The difference in temperature fuels wind action that picks up the dust, then storm emerge from the basin.

The dust storms were of great concern when probes were first sent to Mars. Early probes happened to arrive in orbit during large events. The Viking missions of 1976 easily withstood two big dust storms without being damaged. They were not the first missions to survive Martian dust storms. In 1971, Mariner 9 arrived at Mars during the biggest dust storm ever recorded. Mission controllers simply waited a few weeks for the storm to subside, then carried on with the mission. The biggest issue that rovers face during a dust storm is the lack of sunlight. Without the light, the rovers have trouble generating enough power to keep their electronic warm enough to function.

Mars dust storms are of great interest to scientists. Even though several spacecraft have observed the storms first hand, scientists are no closer to a definitive answer. For now, the storms on Mars are going to continue to present challenges to planning a human mission to the planet.

Here’s an article describing how the dust storms threatened the Mars rovers, and another discussing how electrical dust storms could make life on Mars impossible.

Here’s one of the best articles from NASA about the dust storms, and another gallery from NASA/JPL.

Finally, if you’d like to learn more about Mars in general, we have done several podcast episodes about the Red Planet at Astronomy Cast. Episode 52: Mars, and Episode 91: The Search for Water on Mars.

Sources:
http://science.nasa.gov/science-news/science-at-nasa/2003/09jul_marsdust/
http://www.jpl.nasa.gov/news/news.cfm?release=2007-080
http://science.nasa.gov/science-news/science-at-nasa/2001/ast16jul_1/

Mars Rotation

Mars, just a normal planet. No mystery here... (NASA/Hubble)

Mars rotation is 24 hours, 39 minutes, and 35 seconds if you are interested in the solar day or 24 hours, 37 minutes and 22 seconds for the sidereal day. Since the planet only rotates about 40 minutes slower than Earth, this is one category where the two planets are not very different. Mars, like all of the planets except Venus, rotates in prograde(counter clockwise). The planet has a rotational speed of 868.22 km/h at the equator. The similarity if the length of the day allows the engineers as NASA to switch their day to a ”Mars day” when they are working with rovers on the planet. This maximizes their time with the equipment, but drastically changes their actual Earth schedule. They end up working an ever changing day as the Martian/Earth day difference accumulates.

Mars is a well studied planet. As a matter of fact, it is the best understood planet in our Solar System other than our own. There are currently(July 2011) 6 missions either in orbit or on the planet’s surface. With all of the data accumulated, Mars rotation is only one of thousands of facts known about the planet. Here are a few more.

Multiple missions to Mars have found evidence of water ice and carbon dioxide ice under the planet’s surface. How do scientists know the difference? When the ice is exposed to the Martian atmosphere, carbon dioxide ice(dry ice) will melt and vaporize quickly, in one day or less. Water ice will take up to four days. The other way is to heat a sample in one of the tiny ovens aboard a rover. The spectrometer on the rover will then be able to detect H2O in the gases that the sample releases.

Mars has a reddish appearance because it is covered in rust. Well, iron oxide dust. That dust is every where. Mars has large dust storms that can sometimes cover the entire planet, so that dust is in the air as well. During global dust storms it is impossible to optical observe the surface.

Mars has not had plate tectonics for billions of years, if ever. The lack of plate movement allowed volcanic hotspots to spew magma onto the surface for millions of consecutive years. Because of these uninterrupted eruptions, there are many large volcanic mountains on Mars. Olympus Mons, on Mars, is the largest mountain in the Solar System.

Those are just a few teaser facts. I wish I had more space to keep going, but we have hundreds of more articles about Mars here on Universe Today and do not forget to check out NASA’s website. Good luck with your research.

Here’s an article about how crater impacts measure the ancient equator of Mars. How long is a day on Mars?

Enjoy some Mars facts from NASA, and Hubblesite’s News Releases about Mars.

Finally, if you’d like to learn more about Mars in general, we have done several podcast episodes about the Red Planet at Astronomy Cast. Episode 52: Mars, and Episode 91: The Search for Water on Mars.

Source: NASA

Mars Mass

Earth and Mars. Image credit: NASA/JPL

Mars mass is 6.4169 x 1023 kg. That is slightly more than 10% of the Earth’s mass. Mars is a tiny world in every way when compared to Earth. In our Solar System, Mars is the second smallest planet by mass. Only Mercury is smaller. While Mars is a tiny planet, it is the most explored outside of our own. Here are a few Mars missions and some of the discoveries that each made.

Mariner 3 and 4 were meant to be sister missions to Mars. Mariner 3 failed shortly after launch, but Mariner 4 arrived in Martian orbit after an 8 month journey. It is credited with returning the first images from another planet. It was able to show large impact craters that appeared to have frost on them. The spacecraft and its equipment were crude by modern standards.

We will skip a few missions and move to the Phoenix Lander. This mission’s objective was to confirm the presence of water ice underneath the Martian surface. This water ice had been theorized for quite some time, but lacked confirmation. On June 19, 2008, NASA announced that bits of bright material in a trench dug by the lander’s robotic arm had disappeared over the course of four days. This implied that they were composed of water ice. Initially, they were thought to be water ice or carbon dioxide ice(dry ice) In the conditions on Mars dry ice would have disappeared much faster. Phoenix later confirmed the presence of water ice on Mars using a mass spectrometer. When a soil sample was heated, water vapor appeared as the sample heated to 0 degrees Celsius.

The Mars Express is one of several spacecraft currently exploring Mars. It has sent back images and data the strongly suggest that the Martian environment is much different today than it was a few billion years ago. Interpretation of the data shows that Mars was once a warm and wet world with rivers and oceans dotting its surface. No evidence of past vegetation or life has been found, but proof of liquid water in the planet’s past is intriguing enough.

Knowing Mars mass is enough to answer one question on a test or in a paper, but, to understand the planet, you will have to do quite a bit more research. You will not be alone. NASA scientists are planning at least four more missions by 2020 including a mission to return samples of the Martian soil. The goal is to understand Mars well enough to send a manned flight to the Red Planet.

Here’s a great article about how difficult it will be to land large loads on Mars.

This site lets you calculate your weight on other worlds. And here’s NASA’s fact sheet on Mars.

Finally, if you’d like to learn more about Mars in general, we have done several podcast episodes about the Red Planet at Astronomy Cast. Episode 52: Mars, and Episode 91: The Search for Water on Mars.

Sources:
NASA: Mars Facts
NASA: Mars Missions

Mars Surface

Mar’s surface is a dry, barren wasteland marked by old volcanoes and impact craters. The entire surface can be scoured by a single sand storm that hides it from observation for days at a time. Despite the formidable conditions, Mar’s surface is better understood by scientists than any other part of the Solar System, except our own planet, of course.

Mars is a small world. Its radius is half of the Earth’s and it has a mass that is less than one tenth. The Red Planet’s total surface area is about 28% of Earth. While that does not sound like a large world at all, it is nearly equivalent to all of the dry land on Earth. The surface is thought to be mostly basalt, covered by a fine layer of iron oxide dust that has the consistency of talcum powder. Iron oxide(rust as it is commonly called) gives the planet its characteristic red hue.

In the ancient past of the planet volcanoes were able to erupt for millions of years unabated. A single hotspot could dump molten rock on the surface for millenia because Mars lacks plate tectonics. The lack of tectonics means that the same rupture in the surface stayed open until there was no more pressure to force magma to the surface. Olympus Mons formed in this manner and is the largest mountain in the Solar System. It is three time taller than Mt. Everest. These runaway volcanic actions could also partially explain the deepest valley in the Solar System. Valles Marineris is thought to be the result of a collapse of the material between two hotspots and is also on Mars.

The Martian surface is dotted with impact craters. Most of these craters are still intact because there are no environmental forces to erode them. The planet lacks the wind, rain, and plate tectonics that cause erosion here on Earth. The atmosphere is much thinner than Earth’s so smaller meteorites are able to impact the planet.

Mar’s surface is believed to be much different than it was billions of years ago. Data returned by rovers and orbiters has shown that there are many minerals and erosion patterns on the planet that indicate liquid water in the past. It is possible that small oceans and long rivers once dominated the landscape. The last vestiges of that water are trapped as water ice below the surface. Scientists hope to analyze some of that ice and discover hidden Martian treasures.

How seasonal jets darken the surface of Mars, and how ice depth varies across Mars.

Want to explore the surface of Mars, check it out with Google Mars. Here is some more information about surface features on Mars.

Finally, if you’d like to learn more about Mars in general, we have done several podcast episodes about the Red Planet at Astronomy Cast. Episode 52: Mars, and Episode 91: The Search for Water on Mars.

Sources:
http://solarsystem.nasa.gov/planets/profile.cfm?Object=Mars
http://search.nasa.gov/search/search.jsp?nasaInclude=mars+planet