Fraser Cain, Author at Universe Today

August 16, 2007December 26, 2015 by Fraser Cain

STS-118: Micrometeorite Dings Shuttle Windshield

Just to remind us all that the astronauts are really quite exposed up there in orbit, a micrometeorite took a small chunk out of Endeavour’s front windshield at some point during the mission – the astronauts just noticed it. NASA officials said that the space debris impacted the shuttle’s window #2. With the impact discovered, NASA engineers are planning to study it, but they don’t think it’s a risk to astronaut safety.

Space shuttles have been beaten up by orbital debris in the past. In most cases, the impact is very small, and the impactor is absorbed by the shuttle’s external skin. In this situation, the shuttle is very well equipped with the analysis gear to really study this windshield ding if they wanted to.

As with the foam strike that carved out a slice of Endeavour’s protective heat tiles, the astronauts could use the laser and camera attached to the shuttle’s robot arm to map this micrometeorite damage in exhaustive detail. NASA engineers would then know if it’s of any risk to the astronauts.

Speaking of damage to the shuttle, NASA has decided to push back the next spacewalk for STS-118, now tentatively scheduled for Saturday. With the shuttle pulling power from the International Space Station’s electrical grid, NASA wanted the astronauts to perform a 4th and final spacewalk.

The agency is agonizing over whether or not they should have astronauts attempt to repair the gouge to the shuttle’s belly carved out by falling foam during its launch. If they do decide to proceed with repairs, two astronauts will need to be carried on the end of the shuttle’s robot arm to the underside of the shuttle. They will then try and put in exactly the right amount of heat absorbent caulking to fill the hole. If they get the wrong amount in there, they could even make the problem worse. Not to mention the risk that they could accidentally bump the fragile tiles and do even more damage.

So, get ready for more analysis before a decision gets made.

Original Source: NASA Status Report

August 15, 2007December 26, 2015 by Fraser Cain

Self Organizing Space Dust Could Be a Precursor to Life

As if searching for life wasn’t already difficult enough, physicists now think that clouds of particles in space could mimic the behaviour of life: dividing, replicating and even evolving. This discovery could help scientists understand how life got started here on Earth, and offers intriguing possibilities for life that could evolve in the interstellar clouds of outer space.

This discovery comes from European and Australian researchers, and their work is published in today’s issue of the New Journal of Physics. They developed computer simulations that showed how clouds of molecules naturally organize themselves into complex helix-like structures that resemble DNA.

Over time, an electrical process called polarization organizes the molecules into more and more complex structures. According to the researchers, this suggests a mechanism where organic molecules could assemble faster than in previous models. This shorter time frame means that complex life could be prevalent across the Universe – they get part of the way in space, and then finish off when they reach a planet. Astronomers have already observed vast clouds of these particles out in space with radio telescopes.

Life on Earth requires water, and these molecules wouldn’t have access to the liquid in the near absolute zero temperatures of interstellar space; however, they are able to interact through this polarization process. So there might be a limit, where the structures can’t become complex enough to seed life on young planets. But this process could begin the formation of life, from a random collection of atoms to more complex molecules, and eventually the precursors of life. Evolution could then take over.

Original Source: Science Now

August 15, 2007June 5, 2022 by Fraser Cain

Astrosphere for August 15, 2007

RickJ captured this image Cassiopeia A, the aftermath of a supernova explosion. What’s cool is that you can compare Rick’s version with the Hubble version. You can see the fine details that only space telescopes can get.

Forbes has a very interesting article about the future of NASA.

Ars Technica looks at black holes as a mechanism to constrain the universe.

Phil Plait, the Bad Astronomer calculates that if creationists are correct, the Universe is only 12,000 light years across.

Did you ever get the feeling that you’re living in a simulation?

August 15, 2007December 26, 2015 by Fraser Cain

STS-118: Damaged Glove Shortens 3rd Spacewalk

Shuttle astronaut Rick Mastracchio and International Space Station resident Clay Anderson hurried inside today, cutting their 3rd spacewalk an hour short when Mastracchio discovered that one of his spacesuit gloves had a gash in its outer layers. Even though the rip only penetrated through two of the glove’s five layers, NASA hurried them back inside as a precaution.

Even though the damaged glove ended the spacewalkers’ mission early, they had already completed most of their tasks during their 5.5 hours in space – the mission was supposed to last 6.5 hours. They completed their primary goal, moving an antenna from a temporary position on the P6 truss over to its permanent home on the Unity module. They also moved two rail carts, and added additional antenna parts to improve station communications.

By moving this equipment off the P6 truss, the module can then be relocated from its current position atop the station over to the end of the P5 truss.

The only uncompleted task was to bring in some space exposure experiments that had been running outside the station. Not to worry, these’ll get scooped up on a future spacewalk.

Although this wraps up the three spacewalks that NASA had planned for mission STS-118, NASA is now considering how the rest of the mission will play out. With the shuttle now connected to the International Space Station’s electrical grid, it’s capable of “borrowing” power, and extending its time in orbit up to 14 days. NASA is thinking that another spacewalk may occur on Friday, but could be put off until Saturday. This task might be combined with the installation of a new camera system that’ll help analyze shuttles for damage.

Original Source: NASA Status Update

August 15, 2007December 26, 2015 by Fraser Cain

That’s Not a Comet, that’s a Star

If you take a quick look at the photograph with this story you’d think you’re looking at a comet. I’ve actually got it cut down the image a little to fit the website. To really see the full-sized version, check out this link. Well, that’s not a comet, it’s actually the star Mira, moving so fast through interstellar space that it’s leaving a tail behind.

Mira is an older, red giant star shedding massive amounts of material into space. As the star moves quickly through interstellar space, the particles slow down, and remain as a long tail stretching behind. In fact, this tail is 13 light-years long, or 20,000 times the average distance of Pluto from the Sun.

The image was captured by NASA’s Galaxy Evolution Explorer satellite, and the researchers announced their findings during a NASA press conference today. Their research will be published in the latest issue of the journal Nature.

Billions of years ago, Mira was probably quite similar to our own Sun. As it ran out of hydrogen fuel, the star swelled up, becoming an enormous red giant. It’s known as a variable red giant, and pulsates on a regular basis, puffing up its outer layers and brightening enough to be visible with the unaided eye. Eventually the star will run out of material, and settle down as a white dwarf star.

Since it’s traveling at 130 km/s (80 miles/s), all this material cast off by Mira builds up on the leading side; it creates a bow shock in the front, where sloughed off gas is compressed as it encounters the interstellar winds. The compression causes the gas to heat up and blaze in the ultraviolet spectrum. This material then swirls around behind the star, creating a turbulent, tail-like wake. Since the tail is only visible in the ultraviolet spectrum, it took NASA’s Galaxy Evolution Explorer -which mainly observes in ultraviolet – to find it.

Original Source: Nasa News

August 15, 2007December 26, 2015 by Fraser Cain

Ariane 5 Lofts Two Satellites

Two satellites were carried into space Tuesday evening, atop a massive Ariane 5 rocket, which blasted off from Europe’s Spaceport in French Guiana. The rocket lifted off at 23:44 UTC, and the satellites were put into their geosynchronous transfer orbits 30 minutes later.

On board the Ariane 5 booster were the Spaceway 3 and BSAT-3a satellites. Spaceway 3 was built by Boeing, and will serve as a broadband data communications satellite to customers in North America. BSAT-3a will provide television services to Japan.

Telemetry after the launch confirmed that the two satellites were accurately placed into their transfer orbits, and ground controllers received communications from both satellites, confirming that they’re healthy and operational.

This was the 3rd of 6 planned launches for 2007, and the 19th consecutive successful launch for the Ariane 5 rocket.

Original Source:ESA News Release

August 15, 2007December 26, 2015 by Fraser Cain

Damaged Tiles Aren’t a Risk to Endeavour

With a detailed mock up in hand of the damaged region on the shuttle Endeavour’s underside, NASA engineers have been submitting the area to rigorous tests and computer simulations. Good news. From what they can tell so far, the spot probably isn’t a risk to the safety of shuttle during its reentry, and astronauts probably won’t even need to make repairs.

To perform their experiments, engineers created a duplicate of Endeavour’s damaged section, and then put it into an arc jet. This is a room-sized blowtorch that recreates the conditions of reentry on the shuttle’s tile system. Even though the temperature on the surface of the tiles reached 1090 degrees Celsius (2,000 degrees F), the temperature on the bottom of the gouge only peaked at 170 degrees Celsius (340 degrees F). This is below the limits set by NASA.

However, even if the temperatures remain within tolerance levels, NASA would also want to avoid any lengthy and expensive repairs to the shuttle on the ground, and might get the astronauts to make the repairs. John Shannon, the chairman of the mission management team said on Tuesday that he was “cautiously optimistic” that no on-orbit repairs would be necessary.

As a point of comparison, the suitcase sized chunk of foam that dislodged, and ultimately destroyed the space shuttle Columbia weighed 750 grams (1.67 pounds), while Endeavour’s fragment is thought to be about 100 grams (3.5 ounces). Columbia’s foam strike was on the leading edge of the wing, which experiences some of the hottest temperatures of reentry, while Endeavour’s was down near the landing gear, on a region which is much cooler.

And if you really want to get to know the gouge. Check out this amazing video from NASA that has turned the damaged section into a 3-D animation. You might question their assessment of the risks, but wow, they really know the damage.

August 15, 2007December 26, 2015 by Fraser Cain

Enceladus is an Unlikely Home for Life

When Cassini discovered geysers of water ice fountaining off of Saturn’s moon Enceladus, it was easy to think: life! Wherever we have liquid water here on Earth, scientists have found microbial life thriving; even in the strangest environments. A new model of just how Enceladus generates those geysers has made the possibility of microbial life being able to survive on Enceladus very unlikely.

When the geysers were first discovered, scientists dubbed the process “Cold Faithful”. In this model, tidal interactions between Enceladus and Saturn heat the moon, creating shallow pockets of liquid water under an ice shell. Pressure builds up under the ice, causing it to burst open, and water ice to spray out into space.

But a new model, developed by researchers at the University of Illinois, explains how Enceladus could be producing geyser-like plumes of water ice without an environment hospitable to life. Instead, the process would be called “Frigid Faithful”, and wouldn’t require liquid water at all.

Enceladus is covered in a layer of stiff ice compounds called clathrates, which could go down to a depth of tens of kilometres. Even with a moderately warm heat source underneath the moon’s south pole, these clathrates could deform and create the tiger stripe cracks and fractures which have been observed.

Instead of having pools of water near the surface, these cracks extend down up to 35 kilometres, and maintain almost the exact same temperature all the way down – as cold as 150 degrees below zero. And that wouldn’t be hospitable to life.

So where are the geysers coming from? As the clathrates dissociate, they produce gases that travel up the tiger stripes. This gas then leaks into space, and seen as the plumes that Cassini observed. Here’s what one of the researchers, Gustavo Gioia, had to say:

“This is indeed a frigid Enceladus. It appears that high heat fluxes, geyser-like activity and complex tectonic features can occur even if moons do not have hot, liquid or shifting interiors.”

Original Source: UIUC News Release

August 15, 2007December 26, 2015 by Fraser Cain

Did an Exploding Comet Cause Extinctions 13,000 Years Ago?

Scientists think they might have the solution to a mystery that’s been haunting paleontologists for years: what caused an abrupt period of cooling 13,000 years ago and an extinction of the large mammals. The conventional theory is that when human hunters arrived in North America, they killed off all the tasty large mammals. But there’s evidence that a comet exploded over North America at approximately the same time. This could also cause cooling, and wipe out the animals.

The discovery was made by scientists from the University of California at Santa Barbara. They analyzed more than a dozen archaeological sites across North America, and found they all had high concentrations of iridium. This element is a rare substance on Earth, but known to be in many comets and asteroids. Whenever these objects impact the Earth, they leave a blanket of iridium behind which serves as a marker. As archaeologists dig down through the layers of material, they’re looking back in time, and can accurately date when the object struck.

If this theory is correct, a comet approximately 4 km (2.5 miles) across detonated in the skies above North America, and rained fragments down across the whole region. The extreme temperatures would have ignited wildfires across the continent, destroying the vegetation that the large mammals needed to survive. Their death would then lead to a cascade of deaths by the large predators and the rest of the food chain that relied on them.

The comet might have also destabilized a large portion of the Laurentide ice sheet, causing a high volume of fresh water to flow into the ocean. Climate researchers believe this kind of event can disrupt the normal circulation of the ocean’s flow, and lead to a global cooling event. Ecosystems across the planet would have suffered.

Ancient cultures, such as the Clovis people of North America relied on mammoths and other large mammals for food. They would have been affected by the impact, and this might have caused their culture to die out.

Original Source: NSF News Release

August 14, 2007December 26, 2015 by Fraser Cain

2007 Perseid Meteor Shower Didn’t Disappoint

So, did you heed my advice? Did you set aside Sunday evening to head out with friends and family to enjoy the Perseid meteor shower. Here in Vancouver, we had cloudy skies into the evening. But on a hunch, I set my alarm for 4 am, when the shower was at its height. What a treat.

My kids were disappointed that the sky was clouded over, and we wouldn’t be able to see the meteors Sunday evening. But incredibly, the sky cleared up over night, and it was perfectly clear when I checked outside at 4 am. So, I woke up the kids and we laid out on the back deck and watched for meteors as the skies started to brighten up. I was able to see quite a few before the rising Sun started to brighten the skies too much. All in all, it was great to see.

I’m really looking forward to the next big event: the total lunar eclipse on August 28, 2007. I can’t stress it enough. If you live in the Western North America, the Pacific, or Asia please try and make an event of this eclipse. It’s going to be great.

The European Space Agency has an interesting article about some of the science that happened during the meteor shower, as well as some tests of new equipment that could eventually be used to observer meteors… from space.

Source: ESA News Release