Universe Today

March 18, 2008December 26, 2015 by Nancy Atkinson

Mars’ Violent, Volcanic Past … and Possible Future?

Planetary geologists have a relatively simple method for calculating the age of a planetâ€™s surface: count the number of impact craters in a region. The older the surface, the more craters there will be from meteorites that have struck the planet over the ages. Areas with fewer craters are generally interpreted as younger surfaces where other geological processes such as volcanic activity or plate tectonics, have erased the impact scars. A new analysis of impact cratering using images from the Mars Express has revealed that Mars has undergone at least five violent, global volcanic upheavals, shaping the surface of Mars we see today.

Using the High Resolution Stereo Camera (HRSC) on Mars Express, planetary scientists are learning more about Mars’ past. “We can now determine the ages of large regions and resurfacing events on the planet,” says Gerhard Neukum. Resurfacing occurs when volcanic eruptions spread lava across the planet’s surface. But unlike Earth, where resurfacing happens gradually and slowly, Mars has had a series of violent volcanic periods. This occurred more than 3.8 thousand million years ago. In between these episodes, the planet has been relatively calm.

During these volcanic episodes, eruptions of lava flowed across Mars. The internal heat generated by the volcanic activity also caused water to erupt from the interior, causing wide-scale flash flooding.

Why did Mars behave like this? Geophysical computer-based models suggest that the planet has been trying to establish a system of plate tectonics, as there is on Earth where the crust is broken into slowly moving plates. On Mars, the volcanic episodes represent the planet almost, but not quite, developing plate tectonics.

We recently saw a landslide on Mars. Could we possibly see a volcanic eruption? “The interior of the planet is not cold yet, so this could happen again,” says Neukum.

Original News Source: ESA Press Release

March 18, 2008December 26, 2015 by Nicholos Wethington

New, Unexpected Spots Found on Jupiter

Jupiter is a spotty place. There’s the aptly-named Great Red Spot â€“ a large, long-lasting storm â€“ that we all know and love, and new storms crop up every so often to create interesting features for astronomers both professional and amateur to study. The most recent discovery of new spots can only be seen in the UV, but they add a whole new level of complexity for scientists to chew on.

Io, one of Jupiter’s many moons, is volcanically active, and eruptions on the moon spew sulfur into the system. This sulfur is then ionized and swept up by Jupiter’s strong magnetosphere. Interactions between the ions and the magnetosphere cause aurora in the UV spectrum, similar to the phenomenon that makes the Northern Lights shine here on Earth. Io leaves a so-called ‘footprint’ on Jupiter in this way, and creates a glowing spiral shape on the northern and southern poles of the planet.

The rotation of Jupiter causes the spiral shape of the aurora: Io is ‘connected’ in one spot, and as Jupiter rotates it draws a glowing swirl of UV light around the pole. Astronomers had previously seen spots ‘downstream’ from the main spot caused by the interaction with Io, but these new images show a faint leading spot in front of the main one, essentially “upstream” in the flow of particles that causes the phenomenon.

A team from the University of LiÃ¨ge in Belgium discovered the spots in ultraviolet Hubble images taken of Jupiter. They found that when there were faint leading spots in one of the hemispheres, there were multiple spots in the other. The researchers propose that a beam of electrons is being transferred from one hemisphere to another, causing the fainter spots. The results of the study were published in the most recent edition of Geophysical Research Letters.

The image below illustrates the different mechanisms creating the auroral spots. The large torus around Jupiter is the plume of sulfur created by Io. The blue line between Io and Jupiter is where it is connected by the ionized sulfur, drawn in and funneled by Jupiter’s magnetosphere. The red lines illustrate the possible electron beams connecting the poles, which create the newly-discovered spots.

When Hubble is repaired in August, the researchers hope to take a closer look at the phenomenon and better understand this complex interaction.

Source: Eurekalert

March 17, 2008December 26, 2015 by Ian O'Neill

A Step Toward Quantum Communications with Space

Sending quantum information in the form of qubits (quantum bits) have been successfully carried out for years. Firing indecipherable packets of quantum data (or quantum states) via photons can however degrade the message as the photons travel through the dense atmosphere. Also, the distance of transmitting data is severely hindered by other factors such as the curvature of the Earth. Now, for the first time, Italian scientists have carried out a successful mock single-photon exchange between Earth and a satellite orbiting at an altitude of 1485 km. Although transmission may be restricted here on Earth, the use of satellites will greatly increase the range of such a system, possibly beginning an era of long-distance quantum communication withÂ space.

The key advantage to quantum communications is that it is perfectly secure from being hacked. In a world of security-conscious information transmission, the possibility of sending information hidden in the quantum states of photons would be highly desirable. A major drawback of sending encoded photos here on Earth is the degradation of data as the photons are scattered by atmospheric particles. The current record stands at 144 km for an encoded photon to travel along its line of sight without losing its quantum code. That distance can be increased by firing encoded photons along optical fibres.

But what if you used satellites as nodes to communicate the encoded photons through space? By shooting the photons straight up, they need only travel through 8 km of dense atmosphere. This is exactly what Paolo Villoresi and his team at the Department of Information Engineering, University of Padova with collaborators in other institutes in Italy and Austria hoped to achieve. In fact, they have already tested the “single-photon exchange” between a ground station and the Japanese Experimental Geodetic Satellite Ajisai with some good results.

“Weak laser pulses, emitted by the ground-based station, are directed towards a satellite equipped with cube-corner retroreflectors. These reflect a small portion of the pulse, with an average of less-than-one photon per pulse directed to our receiver, as required for the faint-pulse quantum communication.” – From “Experimental verification of the feasibility of a quantum channel between Space and Earth“, Villoresi et al..

They achieved this feat by using existing Earth-based laser ranging technology (at the Matera Laser Ranging Observatory, Italy) to direct a weak source of photons at the Ajisai, spherical mirrored satellite (pictured top). As the powerful laser ranging beam pinpointed the satellite, it was switched off to allow the weaker encoded laser to fire pulses of data. The two lasers could easily be switched to be sure the Ajisai was receiving the photons. Only a tiny fraction of the pulses were received back at the observatory, and, statistically speaking, the requirement of less than one photon return per laser pulse for quantum communications was achieved.

This is the first step of many toward quantum communications, and it by no means demonstrates the quantum entanglement between two photons (this situation is described in great detail by one of the collaborators in a separate publication) – now thatÂ would be the ultimate form of quantum data transmission!

Source: arXiv, arXiv blog

March 17, 2008December 26, 2015 by Tammy Plotner

Moon and Saturn Team Up On March 19

If you’re watching the gibbous Moon cross the sky on the evening of March 19th, you’re likely to notice a yellowish looking star nearby. That’s not a star. It’s the planet Saturn. For those of you who missed Saturn’s close appearance to last month’s eclipsing Moon, you’ll have another chance to see the pair.

Right now Saturn is making its home in the constellation of Leo, a backwards question marked asterism of stars. If your eyes are sharp and the sky isn’t too bright, you’ll also notice Leo’s brightest star, Regulus, near Saturn as well. Now is a great time to view all three through binoculars. When Galileo first saw Saturn in 1610, his crude telescope couldn’t full resolve Saturn’s rings. He thought Saturn was a blurry triple system – two small orbs on either side of a large one. He reports read, “I have observed the highest planet to be triple.” Yet, the view you’ll get tonight will be the same as when Galileo wrote, “Has Saturn swallowed his children?” the current tilt of Saturn’s rings will be virtually invisible to binoculars.

If you’re thinking this is quite similar to last month’s eclipsing Moon/Saturn appearance, you’d be correct – only this time the pair meet up two days before the Moon reaches full. Saturn takes 29 and a half years to orbit our Sun and its progress through the constellations of the zodiac is very slow. It takes about 2 and half years for it to move from one constellation to the next. Do the math and you’ll find the last time Saturn was in Leo was 1979 and the last time Saturn and the Moon paired was only about 28 days ago.

You won’t have to wait long for the next event, though. For those living in New Zealand and Eastern Australia, be aware that the universal date of March 19th also means a lunar occultation event of Regulus for you! For example those living in Auckland will catch the event starting at 6 11 53 UT and those in Christchurch will see it at 6 28 13 UT. For detailed information on times and locations, go visit the International Occultation Timing Association (IOTA).

Wishing you clear skies…

March 17, 2008December 26, 2015 by Nancy Atkinson

Happy Birthday Vanguard 1, and Welcome Home?

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Jim Oberg has written a very interesting article at MSNBC.com, commemorating the 50th anniversary of the launch of mankindâ€™s fourth artificial satellite, Vanguard 1. While it is no longer functioning or communicating, it is the oldest satellite still in orbit. Jim says, â€œVanguard 1 was the first artificial earth satellite powered by solar cells, and its small suite of instruments provided unprecedented information on Earth’s size and shape, air density and temperature ranges, and the micrometeorite density in space. Tracking its orbit helped geophysicists realize that Earth is not round but slightly pear-shaped, with a slight, symmetric equatorial bulge.â€

Jim has a lot of good history included in the article, but most intriguing, Jim reports Vanguard 1 could become the first satellite brought home, for museum display, by a new generation of robotic space vehicles. That would be incredible! Such an attempt would be a demonstration of robotic space vehiclesâ€™ capabilty, in addition to providing an Earth orbit (and highly exciting) version of retrieving Gus Grissomâ€™s Liberty Bell 7 from the ocean floor. Do check out Jim’s article.

Jim Oberg, of course, is a noted journalist, author, linguist (sorry, inside joke) and space consultant for NBC News.

March 17, 2008April 26, 2016 by Fraser Cain

Preventing Pearl Harbor in Space

Both China and the United States have recently demonstrated their ability to reach out and destroy satellites from the ground. Since the modern military depends so much on satellites for communications and reconnaissance, you can imagine they’re juicy targets in future conflicts. Aviation Week has an interesting article about the US Air Force’s strategy to defend against this.

So here’s the nightmare scenario. One country planning to invade another would launch a simultaneous attack against a constellation of satellites. If the attacker timed things right, and launched enough anti-satellite missiles, the defender would be rendered blind almost instantaneously.

One moment, the Pentagon is watching the Earth from multiple vantage points, coordinating the movement of troops, and a few minutes later… nothing. A 2001 Space Commission called this scenario, “Pearl Harbor in Space”.

The Pentagon is working on a strategy they hope will prevent against this sneak satellite attack, and they hope to have it online by 2011. The new system, called Rapid Attack Identification Detection Reporting System (Raidrs), would upgrade the capabilities of the satellites, as well as put in a ground-based monitoring system. As missiles are launched towards satellites, commanders would have enough warning to move the targeted bird out of the way.

If the attack came today, the US military would know they were being targeted, but they wouldn’t necessarily know where, or from who. And they’d have no way to prevent satellites from being shot down. But within a few years, that should change, with individual satellites able to be defend themselves, and help pinpoint the attacker.

As we move ever forward into the space age, we bring our military with us. Although it would be wonderful to have space without weapons, I can’t imagine why the world’s military wouldn’t want to come along into the final frontier. Space is the ultimate high-ground, and they’ll do everything to defend it. Just imagine how many science probes all this military spending would buy.

Anyway, check out the Aviation Week article, and get more details about the program itself.

March 17, 2008December 26, 2015 by Fraser Cain

Satellite Fails to Reach Proper Orbit

Just a quick piece of sad news. SES Americom reported that its AMC-14 satellite failed to reach its orbit on Saturday after it was launched by a Russian Proton Breeze-M rocket. Despite the failure, though, there might be hope that the satellite will be broadcasting HD television eventually.

The company said that the problem happened during the second burn of the fourth stage, and resulted in the satellite – built by Lockheed Martin – not reaching its geostationary transfer orbit.

With this failure, the company has suspended plans to ship the next satellite to the launch site, and its April launch will be postponed until a thorough investigation can be done. Dish Network was originally planning to lease the entire capacity of the satellite to increase the number of high-definition television channels that it broadcasts. They were planning to launch three new satellites in 2008.

It’s not a hopeless situation, however. SES Americom president Edward Horowitz said he’s working with Lockheed Martin engineers to figure out a way to get AMC-14 back into its correct orbit. The downside is that the fuel used to get the satellite into its proper orbit will shorten its broadcast lifetime, since it’ll have less fuel for station keeping.

Original Source: SES Americom News Release

March 17, 2008 by Fraser Cain

Godzilla Wakeup Call

This is hilarious. You know how NASA beams up a morning wakeup song to the shuttle astronauts on every mission. They decided to go with a giant radioactive lizard theme song for Day 3 of the mission. Japan Aerospace Exploration Agency Astronaut Mission Specialist Takao Doi, and the rest of the astronauts were awoken on Day 3 by this terrifying monster attack on Tokyo.

March 17, 2008December 26, 2015 by Fraser Cain

Advertise on Universe Today, Astronomy Cast, and Other Space Sites

Just in case there are some marketers out there, I wanted to let you all know that you can advertise here in Universe Today, in the Astronomy Cast podcast in the Bad Astronomy/Universe Today forum and other places. If you’re wondering how you can reach almost a million space enthusiasts every month, check out the advertising page. Great demographics and competitive rates. And it’s not just banner advertising either, we can come up with all kinds of clever ideas to help you reach the right audience, including giveaways and interactive programs. Drop me an email at [email protected] with your needs and I can get back to you with some ideas.

March 17, 2008December 26, 2015 by Nancy Atkinson

Making Lunar Soil Usable

Based on what we currently know about the makeup of the lunar regolith, future colonists on the moon will not be able to use the soil on hand to grow food. But in a new experiment, bacteria called cyanobacteria grew quite well in simulated lunar soil. While this wouldn’t be a food source for humans, it would enable lunar soil to be broken down to extract resources for making rocket fuel and fertilizer for crops. This could help with the feasibility of setting up a base on the moon, aiding in reducing costs for certain supplies.

Lunar soil isn’t conducive for growing plants from Earth because many of the nutrients in the soil are locked up in tough minerals that the plants cannot break down. But a group led by Igor Brown of NASA’s Johnson Space Center added the cyanobacteria taken from hot springs in Yellowstone National Park in Wyoming (US), to materials designed to approximate the lunar soil. They found that when water, air and light were supplied, the cyanobacteria grew quite well. Cyanobacteria were found to produce acids that work very well to break down tough minerals, including ilmenite, which is relatively abundant on the moon.

Breaking down the same minerals artificially would require heating them to very high temperatures, which would use precious energy, Brown said. Cyanobacteria, on the other hand, use only sunlight for energy, although they do their extraction work more slowly than heating the soil artificially.

Cyanobacteria typically grow in water-rich environments. They are technically a type of bacteria, but like plants, they produce their own food via photosynthesis.

Brown says he envisions growth chambers for cyanobacteria being set up on the Moon, as part of a multi-step process for making use of the resources bound in the lunar soil. The chambers would be supplied with water, sunlight and lunar soil to allow the cyanobacteria to grow.

Cyanobacteria harvested from the chambers could then be further processed to make use of the elements they extract from the lunar soil. For example, they could be broken down by other bacteria, resulting in a nutrient-rich soup that could be used as fertilizer for food plants grown in hydroponic greenhouses. Methane given off by the breakdown of the cyanobacteria could be used as rocket fuel.

Original News Source: New Scientist