Universe Today

September 21, 2007December 26, 2015 by Fraser Cain

More Martian Cave Entrances Discovered

More Mars news… NASA’s Mars Odyssey spacecraft has turned up what look like the entrances to caves along the slope of a Martian volcano. If these turn out to be actual tunnels or caves, they could be a scientific goldmine, offering future explorers protection and a unique region to study – perhaps even life could be hiding away from hostile Martian surface environment.

The seven possible cave entrances are dark, and nearly circular, ranging in size from 100 to 250 metres (328 to 820 feet) across. They were discovered by NASA’s Mars Odyssey and Mars Global Surveyor spacecraft. Follow up observations with Odyssey’s infrared cameras confirmed that they could very well be cavernous entrances into underground regions on Mars.

The infrared evidence showed that the temperatures inside the holes changed less than the surrounding regions. “They are cooler than the surrounding surface in the day and warmer at night,” said Glen Cushing of the U.S. Geological Survey’s Astrogeology Team and of Northern Arizona University, Flagstaff, Ariz. “Their thermal behavior is not as steady as large caves on Earth that often maintain a fairly constant temperature, but it is consistent with these being deep holes in the ground.”

One of the downsides of these caves is their altitude. They’re located near the top of a massive Martian volcano called Arsia Mons. At this high altitude, life would have a difficult time coping with the extreme cold and lower air pressure.

Planetary geologists think the caves might have been formed by underground stresses around the volcano. The caves are inline with with other bowl-shaped pits that appear to have been formed when material collapsed. There could be long networks of tunnels and stress fractures. In some cases, the roof just collapsed in completely, and in other places, you might get a cave entrance instead.

The next step is to bring the much more powerful Mars Reconnaissance Orbiter’s camera in to image the regions better. It might be able to shed some light on the mystery.

Original Source: NASA/JPL News Release

September 21, 2007December 26, 2015 by Fraser Cain

Martian Southern Cap is Mostly Water Ice

I’ll warn you right now, it’s raining Mars news today. Take cover. First up, we’ve got this interesting story. Planetary scientists at MIT have estimated that Mars’ southern pole contains the largest quantity of frozen water in the inner solar system (apart from the Earth, of course). Many people believed that frozen carbon dioxide was the predominant substance in the south pole’s cap, but nope, it’s water.

The research was led by Maria Zuber, MIT professor of geophysics, and the lead investigator for gravity for the Mars Reconnaissance Orbiter. The project is funded by the NASA Mars Program.

Scientists have long suspected that the Martian southern pole was mostly ice and dust, covered by a thin coating of carbon dioxide, but they didn’t have a firm estimate. Zuber and her colleagues used topographical and gravitational data by three Mars spacecraft to find the volume and mass of the ice cap.

Once they had the volume and mass, they were able to calculate the density. The density of water ice is 1,000 kg per cubic metre, while the density of solid carbon dioxide (aka dry ice) is 1,600 kg per cubic metre. Their estimates calculated that the Martian southern pole is about 1,220 kg per cubic metre. That indicates that it’s mostly water, with about 15% silicate dust mixed in.

This makes the southern polar region of Mars the largest body of water in the inner solar system, outside of the Earth. Just in case that’s not clear, we’re talking about Mercury, Venus and Mars.

One thing that’s still puzzling astronomers is the fact that the polar cap doesn’t reflect as much as you would expect from a coating of ice. It’s believed that the silicate dust mixed in dulls down the cap’s reflectivity.

Zuber and her team are planning to estimate the northern polar cap.

Original Source: MIT News Release

September 21, 2007December 26, 2015 by Fraser Cain

Astrosphere for September 21st, 2007

Hi there, happy equinox tomorrow. Today’s astrophoto was captured by ShevillWMathers. It’s an image of the recent total lunar eclipse – which was clouded out for me. 🙁

First, I’d like to note that the 21st Carnival of Space has gone live over at its original home, Henry Cate’s blog. Henry founded the Carnival of Space, and we’re all grateful for his efforts to keep this organized. Thanks Henry! Speaking of organized, I wasn’t organized enough to get a contribution in.

Astronomy Magazine has a blog. And in this blog, they cover some recent comments by NASA Administrator Mike Griffin about how the US will probably lose the race to return to the Moon. I’m going to daydream about Canadian gumboots making the first steps, but I suspect that’s just wishful thinking.

Frontier Channel reviews the Bionic Woman TV show.

Angela Gunn saw “In the Shadow of the Moon”, and here’s what she thought. New Scientists has a review too.

Dr. Pamela Gay covers research about echoes of radiation from quasars being used to study the centres of distant galaxies.

Space Law Probe discusses the latest in getting electricity from space.

One final note, did anyone catch Seeing in the Dark on PBS? I’ve got it sitting on my PVR. Let me know what you thought.

September 20, 2007December 26, 2015 by Fraser Cain

Lisa Nowak is Having Her Day in Court

Remember Lisa Nowak? She’s the ex-astronaut who drove across the US to confront a rival over the love of another astronaut; a spacey love triangle. Well, things are moving forward now. Nowak testified this week in a court in Orlando, Florida, hoping that key evidence will be thrown out.

Nowak was arrested on February 5th, 2007 after she allegedly sprayed her romantic rival with pepper spray, astronaut Colleen Shipman. Police discovered a bunch of items that could be weapons in her car, including a steel mallet, a serrated knife and a loaded pellet gun. They also found a map of Shipman’s home, garbage bags and latex gloves.

During Tuesday’s hearing, Nowak put forth a motion claiming that the police illegally searched her car, as they didn’t have a warrant. She claimed that she didn’t give the police consent to search the car, and actually misunderstood the charges against her; that she was being charged with an attempted carjacking.

She’s currently charged with attempted kidnapping, attempted burglary and battery, and the actual trial is scheduled to start next year. Whether prosecutors get to include this evidence is the big question.

Nowak’s lawyer has told the court that he’s planning to argue that the astronaut was temporarily insane during the incident, and that she suffers from obsessive-compulsive disorder, partner relational problems and insomnia.

Circuit Judge Marc L. Lubet hasn’t indicated if he’s going to rule on the defense motions yet.

More info, AFP article, ABC News.

September 20, 2007December 26, 2015 by Fraser Cain

Carnegie Mellon’s New Prototype Lunar Rover

Consider this: there are two rovers crawling around the surface of Mars. Isn’t it strange that we don’t have anything similar on the surface of the Moon. I mean, come on, it’s so close. Well, researchers at Carnegie Mellon are working to fix this problem. They’ve been tasked by NASA to develop a prototype lunar rover. One which can travel in the low lunar gravity, and hang on tight when it needs to drill down beneath the lunar soil.

The prototype lunar rover is called “Scarab”, and it’s being built by the Robotics Institute of Carnegie Mellon University’s School of Computer Science. Even though it’s being built to test out technologies designed for the surface of the Moon, this little rover will never make the trip. But its advances will be incorporated into future technologies for real missions.

Traveling around the Moon is going to be hard. Especially when you’re searching for water inside the perpetually darkened craters at the lunar southern pole. You’ve got regions of perpetual darkness at the lunar poles, where temperatures plunge to hundreds of degrees below zero. Instead of the traditional solar panels, Scarab will use a radioisotope source to generate energy.

It won’t get much power, though, probably less than the amount required to operate a 100-watt light bulb. This means that the rover will be operating in nearly complete darkness, relying on low-power, laser-based sensors. And it won’t be fast, crawling forward at only 10 cm/second (4 inch/s).

To be efficient, the rover must be light, but at the same time, it’ll need to have enough mass to let it operate as a drilling platform on the lunar surface. Engineers have calculated tat it needs to weigh at least 250 kg (550 pounds).

The researchers at Carnegie Mellon have been working on the rover since March, developing the structure and programming its software. They’re planning to do a field experiment near the end of the year, where the rover will drive and drill in total darkness.

They’ve also announced plans to enter the new Google Lunar X-Prize, offering $20 million to the first team to land a privately funded robotic rover on the Moon by 2012.

You can learn more about the rover, and see some videos of it in action at the Lunar Rover Initiative website.

Original Source: Carnegie Mellon News Release

September 20, 2007December 26, 2015 by Fraser Cain

Learning How to Stop Dangerous Asteroids

You know the cliche: it’s not a question of if an asteroid will strike the Earth, it’s a question of when. Why wait for the asteroid impact, let’s get out there and learn how to prevent an impact in the first place. Part of this learning process will be to study potential Earth-crossing asteroids in great detail. ESA has just such a mission in the works: Don Quijote.

There are several problems with asteroids. For starters, we don’t even know where they all are. But even when we discover their locations and plot out their orbits, it’s all game of probabilities. Over time, asteroids interact with other objects, and their orbits get changed in ways which are hard to predict. Not only that, but sunlight heats up asteroids in ways that can give them a tiny thrust, so they can change their orbits all on their own.

Astronomers are working hard to catalog all the asteroids out there; automated surveys should find most of the objects larger than 140 metres (460 feet) by about 2020. But plotting out their exact positions, and thus their future trajectories, is the hard part.

So Europe is planning to reach out and tag an asteroid. With a homing beacon, an asteroid will be much easier to track as it moves across the Solar System.

The mission is called Don Quijote, and it will work in two phases. The first phase will consist of an orbiter which will rendezvous with an asteroid and begin circling it. It will monitor the asteroid for several months, studying its size, shape, mass and gravity field.

In the second stage, an impactor spacecraft would slam into the asteroid at a speed of 10 km/s, which the first spacecraft watches – sort of like what happened with Deep Impact. The orbiter could then study the asteroid again, seeing what changed. Ground observers could also make precise measurements on the asteroid’s orbit and determine how its trajectory changed from the impact.

ESA doesn’t have a specific asteroid in mind, but they’re seriously considering a space rock called Apophis, which will come dangerously close to the Earth in the future.

If the mission is approved, it could launch early in the next decade, and take about 25 months to fly to its target. Maybe then we’ll get a much better handle on potentially dangerous asteroids, and learn everything we need to know to prevent them.

Original Source: ESA News Release

September 20, 2007December 26, 2015 by Fraser Cain

Galaxy Leaves New Stars Behind in its Death Plunge

Quick, look at the picture with this story. Are you looking at a comet? Nope, that’s an entire galaxy. But the process is similar. In this case, an entire galaxy is plunging into a galaxy cluster. The interstellar winds are tearing away at its structure, shedding material, and trailing stars behind into a trail 200,000 light-years long. But it’s actually a region of creation, not destruction, as millions of new stars are forming behind the galaxy.

The image you’re looking at was captured by NASA’s Chandra X-ray observatory as well as the Southern Astrophysical Research (SOAR) telescope in Chile. The blue colours are regions bright with X-rays, while the red colours show regions rich in hydrogen gas.

The galaxy is called ESO 137-001, and it’s currently falling into the massive galaxy cluster Abell 3627. The pressure from the intergalactic wind coming from the galaxy cluster is causing gas in ESO 137-001 to heat up to millions of degrees. At the same time, though, hydrogen gas is being stripped out of the galaxy and trailing behind for more than 200,000 light years.

From their observations, astronomers can detect that millions of stars are forming in this galactic tail; the interaction between the gas and intergalactic wind is helping it collapse into massive star forming regions.

By galactic standards, these newly forming stars – most are less than 10 million years old – are going to be very lonely. They’re much further away from their galactic home than stars can ever normally form. Life that might evolve on worlds in those regions would see a few stars in the night sky, and a large haze for their parent galaxy, but otherwise, the sky would seem black.

Original Source: Chandra News Release

September 20, 2007December 26, 2015 by Fraser Cain

New Insights Into Magnetar Explosions

Some of the most extreme objects that we know of in the Universe are magnetars. These are small neutron stars with insanely powerful magnetic fields – they could erase your credit cards from millions of kilometres away. They occasionally have outbursts, blasting out radiation visible from across the galaxy. Now researchers think they have a better handle on where these outbursts are coming from. What’s causing them? That’s still a mystery.

Back in 2003, astronomers watched as a previously unknown neutron star brightened by a factor of 100, briefly becoming visible to a collection of powerful observatories. After detecting pulsations of radiation coming from its surface, astronomers realized they were dealing with a magnetar.

Magnetars were once stars at least 8 times as massive as our own Sun. After the star exploded as a supernova, all that remained was the tiny – but massive – core. The entire mass of the Sun was packed into an object no larger than about 15 km (9 miles across).

Large mass packed into a small area makes it a neutron star, but a tremendously powerful magnetic field puts it into the magnetar class.

The analysis of this new magnetar, known as XTE J1810-197, allowed astronomers to trace the recent outburst to a region just below its surface. In fact, they were able to narrow down the region to an area about 3.5 km (2 miles) across. They could also determine that the magnetic field on the object is about 6 trillion times more powerful than the Earth’s magnetic field.

The process that actually created the outburst is still a mystery. Astronomers are certain that the magnetic field helped trigger the explosion, but they’re not sure what the mechanism is.

Original Source: ESA News Release

September 20, 2007December 26, 2015 by Fraser Cain

Astrosphere for September 20th, 2007

Today’s image was taken by Jamesabrown. It’s a solar pillar, when the Sun’s rays bounce of water vapour in the atmosphere. They’re rare and cool to see.

Mercury is a hard planet to spot. It’s only visible around sunset or sunrise, and either sets quickly or fades into the brightening Sun. There’s going to be a cool pairing on Saturday, September 22nd, when Mercury gets really close to the star Spica. Astroblog has the details.

Centauri Dreams reports that Tau Ceti might not be a terrible place for life after all.

Remember the cool New Mexico spaceport I blogged about last week? Well, the government wants more money to help get it built. From the Personal Spaceflight blog.

Learn how to beam energy to move spaceships at the Fifth International Symposium on Beamed Energy Propulsion. It’s going to be at the Outrigger Keauhou Beach Resort, Hawaii, November 12 – 15, 2007. Nod to Hobbyspace for the link.

September 18, 2007December 26, 2015 by Fraser Cain

Google Moon Gets a Big Update

When Google Moon was released last year, it was a bit of a joke. Google Earth, but for the Moon. Zoom in far enough and the familiar lunar craters were replaced with swiss cheese. The time for silliness is over, Google Moon has gotten an update, and they’re making it a serious learning tool this time around. The website incorporates photographs from orbiters and the Apollo missions to let you zoom in and out, exploring the Moon.

Head over to Google Moon, and follow along. You can change the view between Charts, Apollo, Visible and Elevation. All of the Apollo landing sites are marked on the map, so you can click each one to get more information.

Zoom in all the way, and you don’t see swiss cheese anymore. Instead you see the most detailed images available from NASA showing high resolution details about the landing sites. Each landing site has more than 10 additional detailed place markers, showing points of interest about the mission.

For example, click on the Apollo 16 mission, and the interface informs you there are 21 additional place markers. Click to zoom in, and you can see all the little markers. Click on any one and you’ll see more details, such as interesting rocks, craters, and landing spacecraft. Some of the detailed views are just photographs, but others are panoramas that you can scroll around to see the landscape from the astronauts’ point of view. Very cool!

There are also some landmarks with audio clips and video clips. All in all, the site feels like an educational CD-ROM.

And that’s part of its problem – it’s not really an atlas of the Moon, and more of a presentation of the Apollo missions. Many of those lunar craters have names. There are plenty more interesting features on the Moon than just the Apollo landing sites. I’d love to see some of that information incorporated as well. They could also bring in images from other spacecraft, like ESA’s SMART-1 to provide better coverage in some areas.

My other concern is that it doesn’t really work if you zoom all the way out. Instead of seeing a nice view of the whole Moon, there’s a confusing set of repeating images showing the same portions of the Moon over and over again. Google Maps does the same thing with the Earth, but still, it should look like you’re zooming into the Moon.

Anyway, enough of my review, check it out at http://www.google.com/moon

Original Source: NASA News Release