Universe Today

December 16, 2003March 18, 2013 by Fraser Cain

Mars Gets an X-Ray

Image credit: ESA

The European Space Agency’s XMM-Newton X-Ray Observatory took this recent image of Mars in the x-ray spectrum. Every planet in the solar system, including the Earth, emits x-rays, but scientists aren’t completely sure why. One reason is thought to be “florescence emission”, when x-rays from the Sun hit atoms in our atmosphere and then get re-emitted with a characteristic signature. The bulk of the x-rays in the picture are coming from oxygen in the Martian atmosphere.

Another ESA mission is turning its gaze towards Mars. This recent image was taken by the X-ray observatory XMM-Newton.

All bodies in our Solar System, including planets such as Earth and Mars, emit X-ray radiation. As far as we know, there are several possible sources of this radiation.

One of the main sources is thought to be ?fluorescence emission?. X-rays from the Sun hit atoms of elements such as oxygen in the atmosphere of the planet, and this radiation is re-emitted as so-called ?characteristic? radiation which identifies those specific elements.

This image from XMM-Newton, recorded as part of a study by Dr K. Dennerl (Max Planck Institute for Extraterrestrial Physics, Garching, Germany) shows X-ray fluorescence emission from the atmosphere of Mars, mainly from oxygen. All of these emissions tell us something about the interaction of radiation with the planet’s atmosphere and its environment.

The study of Mars in X-ray wavelengths brings together the work of two very important ESA missions XMM-Newton and Mars Express. Both are crucial to our understanding of our nearest planetary neighbour, demonstrating the coherence of the ESA Science programme.

Original Source: ESA News Release

December 15, 2003July 30, 2007 by Fraser Cain

Book Review: Mars on Earth

For more than three years, the Mars Society has maintained two research stations to test out what would be involved to send a human mission to Mars. In his latest book, Mars on Earth, Robert Zubrin reveals his journey to get the stations built (in the Canadian Arctic and the Utah desert), diary entries from living and working in the stations, and the experience he’s gained about what Martian explorers will go through when they first step foot on the Red Planet.

Robert Zubrin is best known for his earlier book, Case for Mars, where he laid out a revolutionary, and controversial, plan to send human explorers to Mars at a fraction of the cost proposed by NASA. I’ll make an admission right now; The Case for Mars was one of the most influential space exploration books I’ve ever read. Honestly, it rocked my world, so I was eager to catch up with Zubrin and see how the exploration of Mars was going. Another Zubrin book, Entering Space, is more future-looking and speculative, but equally entertaining.

After writing The Case for Mars, and learning of the tremendous amount of support for the concept of human exploration of Mars, Zubrin and some like-minded colleagues went on to found the Mars Society. Since they didn’t have a $50 billion to send a human mission to the Red Planet, the Mars Society has been bootstrapping their way there through a series of simulated Martian missions in two locations: remote Devon Island in the Canadian Arctic, which is one of the best analogs to Mars you can find on Earth; and a location in Utah which is less Mars-like, but offers nearly year-round accessibility. Mars on Earth is a chronicle of Zubrin’s journey from concept to completion of the two Mars research stations and the challenges faced on these first few steps on the way to exploration of the Red Planet.

The first, and largest, part of the book covers the events that led to the final construction of the research stations, and the majority of this is centered around the Flashline Arctic Mars Research Station on Devon Island in the Canadian Arctic. The theme to this part of the book is determination, ingenuity and thriftiness. The Society doesn’t have a lot of money, so they had to come up with clever solutions to overcome the inevitable challenges. Zubrin is a skilled writer, and very opinionated, so this part of the book was quite entertaining to read. During the construction of the station, some relationships were strained beyond their breaking point. Since it’s his book, Zubrin presents his point of view, but there are always two sides to every story. It would have interesting to hear the point of view from the other side of the conflicts. Maybe I’m being a little unrealistic.

The second part of the book consists of a series of status reports that Zubrin filed for the Mars Society and MSNBC while he was working at the two stations over several seasons of research and exploration. These are essentially diary entries covering daily activities on the station and various accomplishments. Since these are already available on the Internet, some readers will have already seen them. It’s nice to have them in one location, and Zubrin connects the reports together with additional information, but some people who followed the Society’s exploits on the Internet might feel a little cheated for content.

The final part of the book is the shortest, and it deals with the lessons he’s learned from his time in the research stations. When you consider the complexity of a human mission to Mars, where the explorers could be on the surface of the Red Planet for more than a year, there’s a mind boggling number of details to consider. If found it really interesting to see Zubrin’s conclusions after having tested some of this stuff out for real. What kind of rovers worked best; communications systems; how stuff broke down; the right role for robots; crew personalities? oh yeah, and bring a bread maker. This stuff is gold. If I had any complaint, it’s that it was too short. Either Zubrin doesn’t have the data gathered yet, or he didn’t want to bore people on which kind of canned meat people like better, but I find these kinds of “lessons learned” very entertaining. It can and should be a book all on its own – maybe a revised edition of The Case for Mars would do the trick.

All in all, I enjoyed Mars on Earth. Zubrin’s enthusiasm for the subject is infectious, and it was very entertaining to read the trials and tribulations he and his team had to overcome to build a little piece of Mars here on Earth.

More Information: Amazon.com – Amazon.ca – Amazon.co.uk

December 15, 2003 by Fraser Cain

Florida Backs Away from Space Lottery Plans

After considering the possibility of giving away a flight to the International Space Station, Florida Lottery officials have decided people would probably just want the cash. The idea of a space lottery had been suggested by Space Adventures, an Arlington, VA company with a contract to sell two seats on upcoming Soyuz flights to the station. Florida Lottery officials didn’t reject the idea outright, but said that prize-based lotteries are never successful – even space enthusiasts would probably take $20 million in cash over a trip to space.

December 15, 2003 by Fraser Cain

Russia Will Be Supplying Station Crews

Russian space officials confirmed this week that they will be delivering new crews to the International Space Station for at least the next year. Russia is planning to launch two missions to the station next year, with guaranteed spots for a Russian cosmonaut and American astronaut on each flight. A Soyuz in April will also carry an astronaut from the European Space Agency, but later flights could be available for tourist flights. Russia is considering five potential tourist candidates.

December 12, 2003 by Fraser Cain

Cassini Collects Particles Accelerated by the Sun

Image credit: NASA/JPL

NASA’s Saturn-bound spacecraft, Cassini, has made the first observation of interstellar pickup ions beyond the orbit of Jupiter. These are neutral particles in the solar system that get ionized when they get too close to the Sun, and then travel outwards with the solar wind. These ions have been seen near the Earth, but never out past the orbit of Jupiter. By measuring these particles, astronomers will have a better understanding of the low-density gas and dust that exists between the stars.

More than a year before the Cassini spacecraft arrives at Saturn, the Cassini Plasma Spectrometer (CAPS) has made the first in situ observations of interstellar pickup ions beyond the orbit of Jupiter. This is the first major discovery using data gathered by CAPS, destined to reach Saturn in July 2004.

Pickup ions are neutral particles in the solar system that become ionized near the Sun and join the solar wind, the supersonic stream of charged particles flowing out from the Sun. By observing these pickup ions, researchers can better understand the interstellar medium, the low-density gas and dust that fill the space between stars.

Astronomers have observed interstellar pickup ions as early as 1985 from a distance of 1 astronomical unit (AU, the distance from the Earth to the Sun), but never before have they seen pickup ions beyond 5 AU — Jupiter’s orbit. The CAPS team uploaded software that allowed the instrument to collect and transmit detections of the relatively rare pickup ions it encounters on its journey to Saturn.

During the observation period of October 2001 to February 2003 at distances of 6.4 to 8.2 AU, the instrument collected 2,627 samples. Analyses revealed that there is a strong depletion of hydrogen pickup ions compared to helium pickup ions in the region behind the Sun. The team determined that this newly observed depletion, or “interstellar hydrogen shadow,” is produced by radiation pressure and ionization of the neutrals. Most hydrogen atoms cannot penetrate into the downstream shadow region because they must pass near the Sun where they have a high probability of being ionized and swept out with the solar wind.

“These are very hard particles to measure because there are so few of them,” says Dr. David J. McComas, senior executive director of the SwRI Space Science and Engineering Division. “Previous models have included something like this interstellar hydrogen shadow, but these are the first direct measurements of it.”

Institute Scientist Dr. David T. Young is principal investigator of the CAPS instrument, the largest, most complex space plasma instrument flown to date, which will detect and analyze plasma (electrons and ions) found throughout the solar system. The overall mission of the Cassini spacecraft is to image the Saturn system at infrared, ultraviolet and visible wavelengths and to directly sample the dust, neutral and charged particle environment. Cassini also carries the Huygens probe, built by the European Space Agency, to study Saturn’s moon, Titan.

“This is certainly the first of many new discoveries to come by the Cassini spacecraft, and the Cassini Plasma Spectrometer in particular,” says McComas. “To have been able to make such an important contribution to heliospheric phenomenon on the way out to Saturn has been a great treat.”

SwRI also leads a feasibility study for the proposed Interstellar Boundary Explorer (IBEX) program, one of five candidates vying to fill two NASA mission slots. If selected, the program would launch a pair of energetic neutral atom cameras to directly image the interaction between the solar system and the interstellar medium – the region that the interstellar neutrals must flow through to enter the heliosphere.

The paper “The Interstellar Hydrogen Shadow: Observations of Interstellar Pickup Ions Beyond Jupiter,” is being presented December 9 at the American Geophysical Union (AGU) meeting in San Francisco and is in press in the Journal of Geophysical Research.

Original Source: SWRI News Release

December 12, 2003 by Fraser Cain

Shuttle’s Wings Will Detect When They’re Damaged

NASA is planning to embed special sensors into the wings of the space shuttle fleet that will detect when they’ve been damaged – it was a foam strike like this that led to the destruction of Columbia nearly a year ago. A member of the safety oversight panel said that the sensors would be able to detect a hit, but not the extent of the damage, so astronauts would still need to spacewalk outside the shuttle to inspect it. Installing these sensors isn’t a requirement for the shuttle’s return to flight, but NASA believes it can have the work done by September 2004 – when the first shuttle is expected to lift off again.

December 12, 2003March 18, 2013 by Fraser Cain

New Doubts Over Dark Energy

Image credit: ESA

It was only a few years ago that astronomers shook up current models of the Universe with the theory of dark energy; which says that the expansion of the Universe is actually accelerating. But new evidence gathered by the ESA’s XMM-Newton X-ray observatory has cast some doubt on the theory. By looking at distant galaxy clusters – up to 10 billion light-years away – the ESA astronomers found they contained more concentrated matter than the theory of dark energy would predict. If matter was so concentrated, the Universe can’t be 70% dark energy.

ESA’s X-ray observatory, XMM-Newton, has returned tantalising new data about the nature of the Universe. In a survey of distant clusters of galaxies, XMM-Newton has found puzzling differences between today’s clusters of galaxies and those present in the Universe around seven thousand million years ago. Some scientists claim that this can be interpreted to mean that the ‘dark energy’ which most astronomers now believe dominates the Universe simply does not exist?

Observations of eight distant clusters of galaxies, the furthest of which is around 10 thousand million light years away, were studied by an international group of astronomers led by David Lumb of ESA’s Space Research and Technology Centre (ESTEC) in the Netherlands. They compared these clusters to those found in the nearby Universe. This study was conducted as part of the larger XMM-Newton Omega Project, which investigates the density of matter in the Universe under the lead of Jim Bartlett of the College de France.

Clusters of galaxies are prodigious emitters of X-rays because they contain a large quantity of high-temperature gas. This gas surrounds galaxies in the same way as steam surrounds people in a sauna. By measuring the quantity and energy of X-rays from a cluster, astronomers can work out both the temperature of the cluster gas and also the mass of the cluster.

Theoretically, in a Universe where the density of matter is high, clusters of galaxies would continue to grow with time and so, on average, should contain more mass now than in the past.

Most astronomers believe that we live in a low-density Universe in which a mysterious substance known as ‘dark energy’ accounts for 70% of the content of the cosmos and, therefore, pervades everything. In this scenario, clusters of galaxies should stop growing early in the history of the Universe and look virtually indistinguishable from those of today.

In a paper soon to be published by the European journal Astronomy and Astrophysics, astronomers from the XMM-Newton Omega Project present results showing that clusters of galaxies in the distant Universe are not like those of today. They seem to give out more X-rays than today. So clearly, clusters of galaxies have changed their appearance with time.

In an accompanying paper, Alain Blanchard of the Laboratoire d’Astrophysique de l’Observatoire Midi-Pyr?n?es and his team use the results to calculate how the abundance of galaxy clusters changes with time. Blanchard says, “There were fewer galaxy clusters in the past.”

Such a result indicates that the Universe must be a high-density environment, in clear contradiction to the ‘concordance model,’ which postulates a Universe with up to 70% dark energy and a very low density of matter. Blanchard knows that this conclusion will be highly controversial, saying, “To account for these results you have to have a lot of matter in the Universe and that leaves little room for dark energy.”

To reconcile the new XMM-Newton observations with the concordance models, astronomers would have to admit a fundamental gap in their knowledge about the behaviour of the clusters and, possibly, of the galaxies within them. For instance, galaxies in the faraway clusters would have to be injecting more energy into their surrounding gas than is currently understood. That process should then gradually taper off as the cluster and the galaxies within it grow older.

No matter which way the results are interpreted, XMM-Newton has given astronomers a new insight into the Universe and a new mystery to puzzle over. As for the possibility that the XMM-Newton results are simply wrong, they are in the process of being confirmed by other X-ray observations. Should these return the same answer, we might have to rethink our understanding of the Universe.

The contents of the Universe
The content of the Universe is widely thought to consist of three types of substance: normal matter, dark matter and dark energy. Normal matter consists of the atoms that make up stars, planets, human beings and every other visible object in the Universe. As humbling as it sounds, normal matter almost certainly accounts for a small proportion of the Universe, somewhere between 1% and 10%.

The more astronomers observed the Universe, the more matter they needed to find to explain it all. This matter could not be made of normal atoms, however, otherwise there would be more stars and galaxies to be seen. Instead, they coined the term dark matter for this peculiar substance precisely because it escapes our detection. At the same time, physicists trying to further the understanding of the forces of nature were starting to believe that new and exotic particles of matter must be abundant in the Universe. These would hardly ever interact with normal matter and many now believe that these particles are the dark matter. At the present time, even though many experiments are underway to detect dark matter particles, none have been successful. Nevertheless, astronomers still believe that somewhere between 30% and 99% of the Universe may consist of dark matter.

Dark energy is the latest addition to the contents of the Universe. Originally, Albert Einstein introduced the idea of an all-pervading ‘cosmic energy’ before he knew that the Universe is expanding. The expanding Universe did not need a ‘cosmological constant’ as Einstein had called his energy. However, in the 1990s observations of exploding stars in the distant Universe suggested that the Universe was not just expanding but accelerating as well. The only way to explain this was to reintroduce Einstein’s cosmic energy in a slightly altered form, called dark energy. No one knows what the dark energy might be.

In the currently popular ‘concordance model’ of the Universe, 70% of the cosmos is thought to be dark energy, 25% dark matter and 5% normal matter.

Original Source: ESA News Release

December 11, 2003December 19, 2015 by Fraser Cain

Best Ultraviolet Image of Andromeda Galaxy

Image credit: NASA

NASA’s Galaxy Evolution Explorer (GALEX) has captured the most sensitive and comprehensive ultraviolet images ever taken of the Andromeda galaxy, M31. By studying the galaxy in the ultraviolet spectrum, astronomers can study some of the fundamental processes that lead the formation of new stars. A new collection of images included Andromeda, as well as the globular cluster M2, and the sky in the constellation of Bootes. GALEX was launched in April, 2003, and will map the sky in the ultraviolet spectrum, looking back to 10 billion years ago.

The most sensitive and comprehensive ultraviolet image ever taken of the Andromeda Galaxy, our nearest large neighbor galaxy, has been captured by NASA?s Galaxy Evolution Explorer. The image is one of several being released to the public as part of the mission?s first collection of pictures.

“The Andromeda image gives us a snapshot of the most recent star formation episode,” said Dr. Christopher Martin, Galaxy Evolution Explorer principal investigator and an astrophysics professor at the California Institute of Technology in Pasadena, which leads the mission. ?By studying this view of the galaxy in the process of forming stars, we can better understand how that fundamental process works, such as where stars form, how fast and why.?

The image of Andromeda, the most distant object the naked eye can see, is a mosaic of nine images taken in September and October of 2003. It combines two ultraviolet colors, one near ultraviolet (red) and one far ultraviolet (blue).

For comparison, a second image shows the Andromeda Galaxy, also called Messier 31, in visible light. Both images, along with other new pictures from the Galaxy Evolution Explorer, are available online at http://www.galex.caltech.edu and http://photojournal.jpl.nasa.gov/mission/GALEX . The new collection of images also includes views of several nearby galaxies; Stephan’s Quintet of Galaxies; an all-sky survey image of the globular star cluster M2; and a deep image of the sky in the constellation Bootes. The Galaxy Evolution Explorer team is also releasing the first batch of scientific data, so the science community can propose additional observations for the mission. These images and data display the power of the Galaxy Evolution Explorer to collect sensitive ultraviolet images of large parts of the sky.

“It?s very rewarding and exciting for the team to see the fruits of their labors,” said Kerry Erickson, the mission?s project manager at NASA?s Jet Propulsion Laboratory, Pasadena, Calif. ?Because people are accustomed to seeing objects in visible light, it?s amazing to see how different the universe looks in ultraviolet and how much information is revealed to us by those observations.?

Scientists are interested in learning more about the Andromeda galaxy, including its brightness, mass, age, and the distribution of young star clusters in its spiral arms. This will provide a tremendous amount of information about the mechanisms of star formation in galaxies, and will help them interpret ultraviolet and infrared observations of other, more distant galaxies.

The Galaxy Evolution Explorer launched on April 28, 2003. Its goal is to map the celestial sky in the ultraviolet and determine the history of star formation in the universe over the last 10 billion years. From its orbit high above Earth, the spacecraft will sweep the skies for up to 28 months using state-of-the-art ultraviolet detectors. Looking in the ultraviolet singles out galaxies dominated by young, hot, short-lived stars that give off a great deal energy at that wavelength. These galaxies are actively creating stars, and therefore provide a window into the history and causes of galactic star formation.

In addition to leading the mission, Caltech is also responsible for science operations and data analysis. JPL, a division of Caltech, manages the mission and led the science instrument development. The mission is part of NASA’s Explorers Program, managed by the Goddard Space Flight Center, Greenbelt, Md. The mission’s international partners are France and South Korea. Caltech manages JPL for NASA

Original Source: NASA News Release

December 10, 2003 by Fraser Cain

Nozomi Has Failed

Image credit: JAXA

The Japan Aerospace Exploration Agency (JAXA) has reportedly given up their efforts to have their Mars-bound spacecraft Nozomi reach the Red Planet. A solar flare in 2002 damaged the spacecraft’s electronics and prevented its thrusters from working properly. Engineers were working up until the last minute, but in the end they weren’t able to get the equipment working again. Nozomi will now follow a wide orbit around Mars and then slingshot out into space. Spacecraft from NASA and the European Space Agency will arrive at Mars over the next couple of months.

The Canadian Space Agency (CSA) today confirmed that the Japanese satellite Nozomi has been rerouted away from Mars by JAXA, the Japan Aerospace Exploration Agency. Crucial orbit insertion manoeuvers were impossible to achieve because of defective equipment onboard and the mission has been canceled. Nozomi will now follow a harmless large elliptic solar orbit.

Canada was a partner in this international Mars mission with a $ 5 million Canadian-built scientific instrument onboard — the Thermal Plasma Analyser (TPA). The TPA was designed to analyse the Martian atmosphere to better understand its origin and composition. The University of Calgary was leading the TPA research team and Canadian firms COM DEV International (Cambridge, Ont.), Pakwa Engineering (Saskatoon, Sask.), CAL Corp. (Ottawa, Ont.) and CompAS Electronics (Kanata, Ont.) were involved in the design and building of the instrument.

“This is not a total loss for the Canadian Space Program”, said Alain Berinstain, CSA’s acting Director of Planetary Exploration and Space Astronomy. TPA has positioned Canada as a preferred supplier of state-of-the-art science and technology. It has opened doors to current and future collaborations with Japan and with other countries involved in the exploration of the solar system. Our thoughts are with our colleagues and friends from Japan and we look forward to working with them again in the future.”

In April 2002, on its way to Mars, NOZOMI had experienced a very strong solar energetic proton event associated with a strong solar flare. This caused a short circuit in one of the subsystems and a loss of telemetry signal, which made the Mars orbit insertion impossible.

Original Source: Canadian Space Agency News Release

December 10, 2003March 24, 2012 by Fraser Cain

Mars Express Has Nearly Arrived

After traveling for more than 400 million kilometres, the European Space Agency’s Mars Express spacecraft has nearly arrived at the Red Planet. Things are about to get pretty busy. On December 19, the Beagle 2 lander will detach from the spacecraft and plunge through the Martian atmosphere six days later. At the same time that Beagle 2 is making its way down to the surface, the Mars Express orbiter will begin its aerobraking maneuvers to get into its final orbit around the Red Planet.

After a journey of 400 million km, ESA’s Mars Express is now approaching its final destination. On 19 December, the spacecraft is scheduled to release the Beagle 2 lander it has been carrying since its launch on 2 June.

At 9:31 CET, ESA’s ground control team at Darmstadt (Germany) will send the command for the Beagle 2 lander to separate from Mars Express. A pyrotechnic device will be fired to slowly release a loaded spring, which will gently push Beagle 2 away from the mother spacecraft.

Data on the spacecraft’s position and speed will be used by mission engineers to assess whether the lander was successfully released. In addition, the onboard Visual Monitoring Camera (VMC) should provide an image showing the lander slowly moving away. The image is expected to be available mid-afternoon.

Beagle 2 will then continue its journey towards the surface of Mars, where it is expected to land on 25 December, early in the morning. At the same time, the Mars Express orbiter should be manoeuvring to enter into orbit around Mars.

In view of the complexity of this operation, the Mars Express control team has been trained to deal with the eventuality that separation might not be achieved at the first attempt. If that did turn out to be the case, there is a series of procedures that has already been set up and tested for completing the manoeuvre successfully within the subsequent 40 hours.

The “separation” event can be followed live at ESA/ESOC on Friday 19 December from 8:30 to 15:00. A videoconference will link the control centre at Darmstadt with ESA Headquarters in Paris (F), and ESA/ESRIN at Frascati (I). Media wishing to attend are asked to complete the attached reply form and fax it to the Communication Office at the establishment of their choice.

Highlights of this event will be streamed over the Internet at http://mars.esa.int at the following times:

09:09 UT – 09:32 UT
11:25 UT – 11.47 UT
12:00 UT – 12:10 UT

As well as live streaming of key events, the Mars Express site will have daily news, features, images, videos and more.

Original Source: ESA News Release