Fraser Cain, Author at Universe Today

July 19, 2007December 26, 2015 by Fraser Cain

Astrosphere for July 19, 2007

Astrophotographer RickJ completes a hat trick. 3 photos in 3 days. This latest one is of cluster Leo I. While he was taking the photo, there were also 5 different asteroids in the picture.

This week’s Carnival of Space #12 is hosted at the Music of the Spheres.

As if flying to space wasn’t expensive enough already. Now the price appears to be going up.

Daily Galaxy has an interesting story about how the Solar System’s position above and below the galactic plane may be dangerous for life on Earth.

Some physics can’t be ignored, but that doesn’t stop science fiction writers.

July 17, 2007December 26, 2015 by Fraser Cain

Satellite Sees Mysterious Noctilucent Clouds

During the summer, observers can sometimes see beautiful clouds called “night-shining” clouds, or noctilucent clouds. And while lucky observers were seeing from below this summer, a NASA satellite was watching them from above.

Noctilucent clouds form in an upper layer of the Earth’s atmosphere called the mesosphere during the Northern Hemisphere’s summer – at an altitude of 80 km (50 miles). They can start forming as early as May, and extend through August. They can also be seen in high latitudes during the summer months in the Southern Hemisphere.

The images were gathered by NASA’s AIM satellite (aka, Aeronomy of Ice in the Mesosphere), which snapped pictures of the clouds on May 25th, 2007.

A puzzling aspect to the phenomenon is that it’s changing dramatically. The clouds are growing brighter, seen more frequently, and visible at lower and lower latitudes than ever before. AIM will observe the clouds above the Earth’s poles for two complete clouds seasons, documenting their entire life cycle to try and help uncover an explanation for this mystery.

Original Source: NASA News Release

July 17, 2007December 26, 2015 by Fraser Cain

Pluto’s Moon Charon has Geysers Too

It’s only been a few months since the discovery of ice geysers on Saturn’s moon Enceladus, and now this dynamic process is turning up all over the Solar System. Astronomers think they’ve found a similar phenomenon on one of the strangest places: welling up from the surface of Pluto’s moon Charon.

The discovery was made using the Gemini Observatory’s adaptive optics system from atop Mauna Kea in Hawaii. The telescope picked out large deposits of ammonia hydrates and water crystals spread out across the surface of the icy moon.

Scientists think that water mixing with ice deep underneath Charon’s surface is causing this material to push up through the moon’s ultra-cold surface. This action could be happening quickly, taking just a few hours or even days. Over time, this process could give Charon a new surface one millimetre thick every 100,000 years. Of course, if Charon has this process going on, something similar could be happening across the Kuiper Belt.

The discoverers believe there’s a dynamic process going on here because Charon’s surface doesn’t appear to be “primordial ice”; ice that was created during the formation of the Solar System. Instead, it’s much more crystalline in appearance, and must have formed recently.

The next step will be to examine other Kuiper Belt objects, like Quaoar and Orcus – both are larger than 500 km (310 miles) across.

Of course, the best thing would be to send a spacecraft and see these bodies up close.

It’s very convenient, then, that NASA’s New Horizon spacecraft is on its way, and will make a flyby in about a decade.

Original Source: Gemini News Release

Go here if you’d like some pictures of Pluto.

July 17, 2007December 26, 2015 by Fraser Cain

Saturn’s Moon Iapetus Enjoys Eternal Youth

Saturn’s moon Iapetus is one of the stranger objects in our Solar System. Unlike other objects its size, Iapetus is walnut-shaped, with a clearly defined chain of mountains along its equator. How could it have formed billions of years ago with the rest of the Solar System, and yet still have its unique shape?

New NASA supported researchers have developed a computer model that seems to accurately explain the series of events that Iapetus went through to arrive at its current shape.

Billions of years ago, shortly after its formation, Iapetus spun quickly, taking just 5 hours to complete a rotation. This fast spin gave it the oblate walnut shape it has today. Over time, its rotation slowed down to about 16 hours. It also cooled down enough that its surface froze solid. It couldn’t absorb the excess surface material. Instead, this rubble built up the chain of mountains around its equator. At this point, its formation completely halted in its tracks. The moon now orbits at a relatively slow rate, turning only once every 80 days.

Scientists were able to confirm these predictions for Iapetus, using observations of its rocks containing short-lived isotopes aluminum-26 and iron-60. These decay at a rate that allowed scientists to carbon date the moon at roughly 4.564 billion years old. About the same age as the Earth.

NASA’s Cassini spacecraft is due to make another flyby of Iapetus on September 10, 2007, passing within only 1,000 km (621 miles) of its surface.

Original Source: NASA Jet Propulsion

July 17, 2007December 26, 2015 by Fraser Cain

NASA is Sending a Phoenix to Mars

Since the launch of the Mars Phoenix Lander is just around the corner, I thought I’d give you a quick explainer on the mission.

So, let’s get into it. Meet NASA’s Mars Phoenix Lander. Scheduled for launch on August 3rd, this mission will blast off from Cape Canaveral atop a Delta II rocket. It’ll take almost 10 months to reach Mars, entering the atmosphere in May, 2008.

The spacecraft is equipped with a pulsed thrust system to slow its descent through the atmosphere. Its landing system is pared down to the bare essentials to maximize the amount of scientific equipment it can land with. It doesn’t have an airbag system like the rovers, and instead will use parachutes and thrusters to land gently on the surface on its three landing legs.

Unlike the Mars rovers currently crawling around the surface of the Red Planet, Mars Phoenix Lander will be stationary. Once it touches down in the Martian polar regions, it’ll live out the rest of its days searching from that position.

Its purpose is to determine if life ever arose on the surface of Mars, or even there’s life there today. Although the surface of Mars is cold, dry, scoured by wind and dust, and blasted by radiation from the Sun and space, just underneath the topsoil, there could water ice and even life, protected from the harsh elements.

The Phoenix Lander will use its 2.3 metre (7.7 feet) folding arm to dig down into the Martian soil around its landing site. NASA’s Mars Odyssey spacecraft revealed that there are large deposits of water ice just a few centimetres beneath the surface of Mars. The Phoenix Lander should be able to break through into this crust, and see if there’s anything alive down there.

The robotic arm will lift the soil samples up onto the main spacecraft deck so that a suite of scientific instruments can examine it for evidence of life. One will heat the samples, and measure the kinds of gases given off. Another will analyze the chemistry of the soil itself.

In addition to its search for evidence of past and present life, Mars Phoenix Lander will serve as a Martian weather station, following changes in the polar regions to help scientists predict weather patterns on the Red Planet.

Good luck Mars Phoenix Lander.

Original Source: NASA/JPL News Release

July 17, 2007December 26, 2015 by Fraser Cain

Astrosphere for July 17, 2007

Today’s wonderful astrophoto is from RickJ. That’s two in two days Rick; nice going. It’s a snapshot of M81, tearing apart another galaxy, Holmberg IX

Beverly Spicer at EarthSkyBlogs writes about a really cool World Clock

It’s the myth that just won’t die. I’ve already written about this every single year for 4 years now. But nope, the rumour’s going around again. Mars as big as the moon!

Charles Daney gives the science explainer on axions; hypothetical particles that could explain dark matter.

Here’s a timeline of climate change events for the 21st century.

Apparently we’ve got a deadline. According to the New York Times, we’ve got to get a colony established on Mars within 46 years… or else.

July 17, 2007December 26, 2015 by Fraser Cain

Large Outer Planets are Rare

One of the big surprises the Universe had in store for extrasolar planet hunters is the number of enormous planets close into their parent stars – the hot Jupiters. Another surprise seems to be how few large planets are found in the outer reaches of a solar system.

The discovery was announced by an international team of astronomers who concluded a three-year survey of 54 young, nearby stars. These should be among the best candidates to have large, Jupiter-sized planets further than 5 astronomical units from their parent stars (1 astronomical unit is the distance from the Earth to the Sun).

They didn’t find a single planet.

Using the European Southern Observatory’s powerful telescopes, such as the 8.2-metre Very Large Telescope (VLT) in Chile, the team had the ability to find outer super Jupiter planets at distances of more than 10 astronomical units from their stars. They had the imaging capability to spot them, but none turned up.

This new data helps astronomers constrain their calculations about where and how giant planets form in other solar systems. They can refine their models to better understand how our own giant planets might have formed.

Original Source: UA News Release

July 17, 2007December 26, 2015 by Fraser Cain

Podcast: The Important Numbers in the Universe

This week we wanted to give you a basic physics lesson. This isn’t easy physics, this is a lesson on the basic numbers of the Universe. Each of these numbers define a key aspect of our Universe. If they had different values, the Universe would be a changed place, and life here on Earth would never have arisen.

Click here to download the episode

The Important Numbers in the Universe – Show notes and transcript

Or subscribe to: astronomycast.com/podcast.xml with your podcatching software.

July 16, 2007December 26, 2015 by Fraser Cain

European Columbus Module Preparated for Atlantis Mission

With the shuttles back to their regular flight schedule, NASA is working through the backlog of components they need to attach to the International Space Station. One of the important ones will be the Columbus space laboratory, developed by the European Space Agency.

Columbus was flown to Florida back in May, 2006, to get in line for its launch to the station. Earlier this year, it was removed from temporary storage, and engineers equipped it with experiment racks and orbital hardware. After a break over the summer, workers will continue preparing it for launch. If all goes well, it will blast into space atop the space shuttle Atlantis as early as December 6th, 2007.

The module was originally supposed to launch in 2002, but the Columbia disaster and the station construction delays pushed the schedule back 5 years.

Original Source: ESA News Release

July 16, 2007December 26, 2015 by Fraser Cain

Building an Engine that Can Throttle Down

Here on Earth, we’ve gotten used to the concept of a car’s accelerator pedal. Put it down a little, and the car accelerates slowly. Put the “pedal to the metal” and you’ll go faster. Imagine trying to park your car when you only have two choices: off and full speed. Developing a similar concept for a rocket is very difficult. Most rockets are designed to go at full blast, or nothing at all.

A variable acceleration rocket would tremendously useful for landing on the Moon. Instead of firing the landing rockets in short bursts, astronauts could throttle down for a nice smooth landing. But building an engine like this is harder than it sounds.

NASA researchers think they’ve got a prototype engine that should give the variable rate of acceleration astronauts are looking for. The newly developed Common Extensible Cryogenic Engine (CECE) is a variant on the RL10 engine that boosted the Surveyor robot landers to the Moon back in 1966-68. The RL10 is designed to only go full throttle, so adding the variable thrust was difficult.

The main problem is that changing the throttle affects how the whole engine functions. At low power, liquid hydrogen can slow and vapourize in the coolant lines. This might cause the engine to stall. During one test, the experimenters discovered that the engine “chugged”, vibrating 100 times a second. It turned out oxygen vapours were forming on the injector plate, inhibiting normal flow, causing the vibrations.

It’s not ready for space yet, but CECE might eventually become part of the design of a future lunar lander. The astronauts returning to the Moon will be very appreciative.

Original Source:Science@NASA