Universe Today (Page 541)

One of the most mysterious places in the Solar System is right underneath your feet: the interior workings of the Earth. Since it's impossible to drill down more than a few km under the surface of the Earth, scientists have study how sound waves from earthquakes travel throughout the planet and get reflected as they bump into things. These sound waves have always acted differently than predicted in simulation. Scientists now think that iron, crushed under tremendous pressure, can significantly alter the speed and direction of these sound waves.

Discovery Set to Launch Tuesday Morning

By Fraser Cain - July 21, 2005 02:29 AM UTC | Missions

Engineers are still working to troubleshoot a malfunctioning fuel gauge on the space shuttle Discovery's external tank, but NASA has pinned down a launch date anyway. If all goes well, Discovery is expected to lift off on Tuesday, July 26 at 1439 UTC (10:39 am EDT). Even if the fuel sensor fails again, managers will go ahead with the launch, as they don't believe there's a risk to the shuttle - there are 3 additional sensors that perform the same task.

A Supernova that Won't Fade Away

By Fraser Cain - July 21, 2005 02:04 AM UTC | Stars

Supernovae are powerful stellar explosions that flare up brightly and then slowly fade away. But not always. One supernova, that exploded in 1979, is blazing as brightly in X-rays as it did when it was first discovered. The discovery was made using the ESA's XMM-Newton space telescope. Scientists speculate that a powerful solar wind is smashing into previously ejected material, heated it up until it glows brightly. This is like a powerful light illuminating the whole area, and allowing the astronomers to study the whole area for years and see how it changes over time.

Dusty Disk Could Hide a New Earth

By Fraser Cain - July 21, 2005 01:55 AM UTC | Exoplanets

Astronomers have used the massive Gemini and W.M. Keck observatories to discover a Sun-like star with one of the warmest, dustiest environments ever seen. The disk around star BD +20 307 is warmer than most other planetary disks because there have probably been recent collisions between planets. In fact the heat is so high, the researchers think a collision recently occurred that matches a cataclysmic event in the Earth's past when a Mars-sized object smashed into our planet, and spun off material that became the Moon.

Search for Mars Methane

By Fraser Cain - July 20, 2005 12:38 PM UTC | Planetary Science

Since scientists announced the discovery of methane in the atmosphere of Mars last year, there has been a controversy about whether this is an indication of life on the planet or not. Methane should only last a few hundred years in the Martian atmosphere before it breaks apart, so some source is continually producing it. On Earth, the main source of methane is from life; mainly microbes. But could there be some other natural geological process on Mars keeping this gas in the atmosphere?

July 26 Targeted for Discovery Launch

By Fraser Cain - July 20, 2005 12:06 PM UTC | Missions

NASA is targeting July 26, 2005 as the earliest date for the space shuttle Discovery to return to flight. Engineers are still working through a troubleshooting plan to get to the bottom of a problem with a liquid hydrogen low-level sensor circuit that forced managers to abort the launch last week. Discovery's launch window lasts until July 31, and then opens up again in September.

Charon Passes in Front of a Star

By Fraser Cain - July 20, 2005 04:02 AM UTC | Planetary Science

Astronomers from MIT and Williams College have teamed up to capture an event seen only once, 25 years ago. On the night of July 10/11, Pluto's moon Charon briefly passed in front of a distant star - this is called an occultation. By studying how the light from this star dimmed and then brightened again, the astronomers will be able to determine if Charon has an atmosphere. Charon is small, so it doesn't have much gravity to hold an atmosphere, but it's so cold that some gasses could be held in place.

Astrophoto: Venus Transit by Adam Steiner

By Fraser Cain - July 20, 2005 03:30 AM UTC | Observing

How Millisecond Pulsars Spin So Fast

By Fraser Cain - July 20, 2005 01:41 AM UTC | Stars

Observations with the Chandra X-Ray Observatory have given astronomers some clues about what causes millisecond pulsars - extremely dense stars which can spin many times a second. Several of these pulsars were discovered in a stellar cluster called 47 Tucanae, where the stars are less than .1 light years apart. Astronomers think these pulsars started as regular neutron stars, but tightly joined with stellar companions they picked up in the cluster. Eventually they get so close they start drawing material off the companion, which causes them to speed up.

Biggest Star Quake Ever Seen

By Fraser Cain - July 20, 2005 01:00 AM UTC | Stars

On December 27, 2004, a neutron star flared up so brightly, it temporarily blinded all the X-ray satellites in space for an instant, and lit up the Earth's upper atmosphere. This tremendous blast of energy was from a giant flare created by the neutron star's twisting magnetic field. Objects like this are called magnetars, and they produce magnetic fields trillions of time more powerful than those here on Earth. These fields are so strong they can actually buckle the surface of the neutron star causing these powerful star quakes.

Oldest Planetary Disk Discovered

By Fraser Cain - July 19, 2005 12:32 PM UTC | Exoplanets

Astronomers from the Harvard-Smithsonian Center for Astrophysics have found a dusty disk around a star which is 25 million years old. Planetary disks like this have been seen before, but never around a star which is so old; it's possible it'll never form planets. Most planetary disks make the transition within just a few million years, and the previous record was 10 million years. The disk still has a lot of gas in it, so researchers think it's still possible that it could form gas giants.

Melt Through the Ice to Find Life

By Fraser Cain - July 19, 2005 06:19 AM UTC | Astrobiology

Scientists can tell us what our climate on Earth was like in past by examining ice cores taken from glaciers. Tiny bubbles of air are trapped in the ice and maintain a historical record of ancient atmospheres. The effects of life make their mark in these ice samples as well. What if you examined the icecaps on Mars, or the layers of ice on Europa? NASA is considering a proposal for a small spacecraft that would land on Mars or Europa and melt its way throught the ice, collecting data as it descended, searching for clues about the presence of life.

Cyborg Astrobiologist Could Help Astronauts Find Life on Mars

By Fraser Cain - July 19, 2005 05:47 AM UTC | Astrobiology

When humans first step onto the surface of Mars in the coming decades, they'll be like kids in a candy store; so many rocks to turn over or chip away at. Is that discoloured patch algae? A team of Spanish engineers are working on a Cyborg Astrobiologist that could help observe the landscape with a video camera, see what the astronauts see, and suggest places that might be interesting for further study. Larry Klaes reports on this interesting new technology, but he thinks robots could use a system like this even sooner.

Tethys Glides Past Saturn

By Fraser Cain - July 19, 2005 01:46 AM UTC | Planetary Science

NASA's Cassini spacecraft took this picture of Saturn with its moon Tethys in the foreground. Tethys is 1,071 (665 miles) across. Cassini took this image on June 10, 2005 when it was approximately 1.4 million km (900,000 miles) away from Saturn.

Return to Flight Launch Pushed Back at Least a Week

By Fraser Cain - July 18, 2005 12:23 PM UTC | Missions

Space Shuttle managers have announced that Discovery won't be lifting off until late next week, at the earliest. Engineers and managers are still trying to troubleshoot exactly what caused a problem with the external tank's fuel gauge. It's possible that one of the new safety improvements, implemented as part of the Return to Flight effort might be causing the glitch. If the shuttle doesn't launch by July 31, it will need to wait again until September before there's another opportunity.

Canada's Humble Space Telescope

By Fraser Cain - July 18, 2005 12:03 PM UTC | Telescopes

One of the more productive telescopes in space is the tiny Canadian MOST satellite (Microvariability and Oscillations of Stars). Developed and maintained on a shoestring - $7 million USD - MOST is only the size of a suitcase, but it has a very sensitive instrument which can detect the variations in star brightness. MOST has been used to analyze recently discovered extrasolar planets as they pass in front of their parent stars, and even get some information about their atmospheres.

What's Up This Week - July 18 - July 24, 2005

By Fraser Cain - July 18, 2005 04:21 AM UTC | Site News

Greetings, fellow SkyWatchers! We'll begin this week by watching the dance of Venus and viewing beautiful star system Omicron Cygni. Although the Moon goes full this week, we can still take pleasure in exploring its bright ray systems. Need more? Then let's have a look at Epsilon Lyrae and 61 Cygni. Simply stargazing during the warm summer nights can bring its own rewards, for the Aquarid meteor shower is highly active. So turn your eyes to the skies, because...

Here's what's up!

Book Review: Reflections from Earth Orbit

By Mark Mortimer - July 18, 2005 04:12 AM UTC | Space Exploration

Some children do grow up and become space travellers. Along the way a series of powerful experiences may act as propellants, advancing them into the future. Winston Scott in his book Reflections from Earth Orbit warmly expresses his memories, from watching Saturday morning cartoons with his brother to undertaking EVA's with NASA colleagues. This sharing of his experiences and personal highlights allows an inside look into one person's advancement into space travel.

Pandora and Prometheus

By Fraser Cain - July 18, 2005 01:07 AM UTC | Planetary Science

In this nearly side-view of Saturn's rings, it's possible to see the two ring shepherd moons: Pandora (right) and Prometheus (left). Saturn's F ring extends out to the far right, and contains a large amount of fine, icy material that is probably the size of dust, unlike the B ring which has boulder-sized objects in it. This picture was taken when Cassini was 1.85 million km (1.15 million miles) away from Saturn.

Strange White Streak on Titan

By Fraser Cain - July 15, 2005 12:12 PM UTC | Planetary Science

During a recent flyby of Titan, Saturn's largest moon, NASA's Cassini spacecraft got a good look at the bright Xanadu region - where the Huygens probe landed earlier this year. One unusual feature is the strange bright line, which scientists are calling the "smile". This 560 km (345 mile) long feature is quite bright in several of Cassini's instruments; in both visible and infrared wavelengths. It's exact nature is still unknown, so scientists will continue to gather evidence from future flybys.

APEX Telescope Sees First Light

By Fraser Cain - July 15, 2005 11:04 AM UTC | Telescopes

The Atacama Pathfinder Experiment (APEX) achieved a new milestone this week when it made its first observations. APEX consists of a 12-metre telescope designed to view the Universe at submillimeter wavelengths: a part of the radio spectrum especially useful for viewing colder objects. APEX is the same instrument that will eventually go into the much larger ALMA project, which will consist of at least 64 of these telescopes, arrayed to function as a single instrument.

Nicholson Crater on Mars

By Fraser Cain - July 15, 2005 02:45 AM UTC | Planetary Science

The European Space Agency's Mars Express has taken an new photograph of Nicholson Crater, located at the southern edge of Amazonis Planitia on Mars. This crater is 100 km (62 km) across and has a very large raised central mount. Large craters often have this kind of central peak, which forms when material rebounds after a meteor impact, but Nicholson Crater's peak is heavily eroded by wind and water.

Martian Dust Devils Will Plague Astronauts

By Fraser Cain - July 15, 2005 02:08 AM UTC | Planetary Science

When the first astronauts set foot on Mars, they'll need to keep a nervous eye out for the many dust devils that crisscross the surface of the Red Planet. In fact, if you were standing next to NASA's Spirit rover in the middle of the Martian day, you might see 6 dust devils zipping across the landscape. While they wouldn't be dangerous, these devils are electrified, and could disrupt communications, damage electrical devices, and clog up spacesuits with statically clingy Martian dust that would be very difficult to remove.

Discovery Won't Launch Before Sunday

By Fraser Cain - July 15, 2005 01:01 AM UTC | Missions

NASA has announced that the space shuttle Discovery's earliest launch window will be on Sunday, July 17 at 1914 UTC (2:14 pm EDT); although, it could be much later. A problem with a fuel gauge on the shuttle's external tank halted the countdown on Wednesday. Engineers have so far been unable to find the source of the problem. The shuttle's launch window will last until the end of the July, and then opens up in September again.

Satellite Can Tell When Ice is Melting

By Fraser Cain - July 14, 2005 12:48 PM UTC | Planetary Science

The analysis software that NASA uses to inspect photographs of the Earth is starting to recognize changing events on our planet's surface, like Spring thaws, snowfalls and volcanic eruptions. In fact, the software is now giving orders back to NASA's Earth Observing-1 satellite on where it should be pointing its camera. The software has taken more than 1,500 photographs of frozen lakes and can recognize when the ice has melted. Software like this could be used to track changing events on other planets, like dust storms on Mars or search for ice volcanoes on Europa.

Planet Found in Triple Star System

By Fraser Cain - July 14, 2005 12:35 PM UTC | Exoplanets

A backdrop in many science fiction stories is to have multiple suns in the sky. Astronomers have now found such a world, called HD 188753 Ab. Our heroes couldn't set foot on this planet, though, since it's a "hot jupiter"; roughly the mass of Jupiter, but orbiting its parent star every 3.3 days. The other two stars in the system take 25.7 years to orbit the main star (about the distance from the Sun to Saturn), and spin around each other every 156 days,

Superwinds Seen in Distant Galaxies

By Fraser Cain - July 14, 2005 12:18 PM UTC | Extragalactic

Astronomers have discovered a massive explosion in a galaxy 11.5 billion light years away. This explosion is producing streams of high speed material called "superwinds" which are nearly tearing the galaxy apart. These explosions are thought to put a limit on the amount of star formation that can happen in any galaxy, since these superwinds will blow excess gas and dust out into intergalactic space. This helps explain why key elements needed for the formation of planets and life were well distributed in galaxies so early on in the history of the Universe.

Malfunctioning Fuel Gauge Delays Shuttle

By Fraser Cain - July 14, 2005 12:00 PM UTC | Missions

The return to flight launch of the space shuttle Discovery was delayed Wednesday when a faulty fuel gage failed a prelaunch check. The shuttle actually has four of these sensors for redundancy, but they all need to be working for the shuttle to get cleared for launch. The launch window has been pushed back to Saturday, July 16 at 1940 UTC (2:40 pm EDT). When it finally gets off the ground, Discovery will deliver supplies to the International Space Station and test new safety procedures developed for the Return to Flight.

Cluster Spacecraft Give Each Other Some Room

By Fraser Cain - July 14, 2005 01:14 AM UTC | Missions

The European Space Agency's fleet of 4 Cluster spacecraft put a little more distance between each other, during a difficult repositioning maneuver completed this week. Three of the spacecraft were separated to 10,000 km from each other, with the fourth moving 1,000 km away from the third. By shifting the distance of the spacecraft, from 100 km to 5,000 km, and now 10,000 km, scientists are able to study the Earth's magnetic field at different scales. This maneuver also marks the fleet's fifth year of operation.

Will We Find Super Earths?

By Fraser Cain - July 13, 2005 12:58 PM UTC | Exoplanets

As techniques and equipment for finding extrasolar planets improve, astronomers are finding planets with smaller masses. First it was Jupiter-sized planets and larger, then Saturn-sized planets, and now Neptunians. But could these Neptune-mass planets actually be terrestrial planets, made of rock instead of gas and ice? Unlike Neptune and Uranus, these planets orbit very close to their host star. Astronomers will need to find one that transits in front of its host star to they can determine its density, to know if it's rock, ice or gas.

Three Space Telescopes Find a Neutron Star

By Fraser Cain - July 13, 2005 03:18 AM UTC | Telescopes

An international team of astronomers have discovered a hidden neutron star using three different space observatories: Integral, Swift and Rossi. The object, called IGR J16283-4838, is part of a binary system which is shrouded in thick layers of dust that obscure our view from Earth. Astronomers were able to detect it because it released a blast of gamma and X-rays that penetrated this shroud of dust. It took all three observatories to pin down the source of this blast of radiation as a neutron star.

Prometheus Shepherding the Rings

By Fraser Cain - July 13, 2005 02:58 AM UTC | Planetary Science

In this beautiful image, Saturn's shepherd moon Prometheus hovers above the planet's A and F rings. It's also possible to see bright clouds on the surface of Saturn, passing through the ring shadows. This photograph was taken by NASA's Cassini spacecraft on June 3, 2005, when it was approximately 2.1 million km (1.3 million miles) away from Saturn.

Supercomputer Will Study Galaxy Evolution

By Fraser Cain - July 13, 2005 01:16 AM UTC | Milky Way

A new supercomputer has been installed at the Rochester Institute of Technology to simulate the interactions between black holes and the evolution of galaxies. Known as the gravitySimulator, this computer will run simulations that calculate the gravitational interactions between thousands of individual stars. It can achieve a top speed of 4 Teraflops (4 trillion floating point instructions a second), making it one of the top 100 supercomputers in the world.

Sloan Digital Sky Survey, Part II

By Fraser Cain - July 12, 2005 12:30 PM UTC | Observing

The Sloan Digital Sky Survey (SDSS) is a comprehensive view of the night sky gathered by a dedicated 2.5 m telescope in New Mexico. Astronomers have used this vast database to make many discoveries about our Universe. And now it's going to have a sequel. SDSS II will be a new survey beginning in 2008, and consisting of three parts: a continued mapping of deep space to image distant galaxies and quasars; a detailed survey of our own Milky Way galaxy; and a study of supernovae, to try and help pin down the mysterious dark energy accelerating our Universe.

Strange Hyperion Looks Like a Sponge

By Fraser Cain - July 12, 2005 12:00 PM UTC | Planetary Science

NASA's Cassini spacecraft has gotten a good look at Saturn's unusually shaped moon Hyperion. It has many fresh craters, giving it a spongy looking appearance. Scientists estimate that the moon is only 60% as dense as water, which means that much of its interior must be completely empty space. The images were gathered during a recent Hyperion flyby, when Cassini came within 168,000 km (104,000) of the moon.

Astronomy Hacks Giveaway

By Fraser Cain - July 12, 2005 10:43 AM UTC | Site News

Old NASA Equipment Will Be Visible on the Moon

By Fraser Cain - July 12, 2005 03:01 AM UTC | Missions

During the Apollo era of spaceflight, many US spacecraft and vehicles were left on the Moon when the astronauts returned home. For the first time in more than 30 years, we'll get a chance to see them again when NASA's Lunar Reconnaissance Orbiter arrives at the Moon in 2008. It will be equipped with a camera capable of resolving the surface of the Moon down to half a metre (1.6 feet). Some of the larger structures on the Moon are 9 metres (30 feet) across, so they should be easy to spot by the orbiter.

Deep Impact's Plume Was Bigger Than Expected

By Fraser Cain - July 11, 2005 11:22 AM UTC | Planetary Science

When Deep Impact's impactor slammed into Comet Tempel 1 on July 4, 2005, it released a tremendous cloud of fine powdery material from the comet's nucleus. Scientists are still studying the volumes of data acquired by Deep Impact, but it appears this plume was much brighter than anyone had expected; its surface was more like talcum powder than sand. The crater was probably on the large side of what was being predicted: 50 - 250 metres (165 - 820 feet).

What's Up This Week - July 11 - July 17, 2005

By Fraser Cain - July 11, 2005 06:08 AM UTC | Site News

Greetings, fellow SkyWatchers! It will be busy skies this week as the Moon goes through a series of occultations for viewers around the world - be it a star, Jupiter or even a comet! We'll begin by exploring the "Butterfly Cluster" and work our way through some new lunar features as the week progresses. The dance of Venus and Mercury continues, so open your eyes to the skies, because...

Here's what's up!

Book Review: Astronomy Hacks

By Mark Mortimer - July 11, 2005 05:31 AM UTC | Site News

Hacking sounds crass. It manifests images of short cuts, jobs poorly done and people most interested in just finishing, no matter what. In the computer industry, sometimes this perfectly portrays hackers. However, for an expert, a hack is the complete opposite. It's a beautiful, well thought resolution that uses minimal effort. Often only those in the know truly appreciate it. Robert and Barbara Thompson in their book, Astronomy Hacks compile tips and techniques for observing the night sky. Their methods seem simple, yet they include detail to show they are experts who are presenting hacks derived from years worth of knowledge.

Japanese Astro-E2 Satellite Launched

By Fraser Cain - July 11, 2005 03:10 AM UTC | Missions

The Japanese space agency JAXA announced the successful launch of the ASTRO-E2 X-ray satellite on Sunday. A Japanese-built M-5 rocket blasted off from the Uchinoura Space Center carrying the Astro-E2 into orbit. This satellite, renamed Suzuka, is a replacement for the Astro-E satellite, which was destroyed because of a launch failure in 2000. Once it's operational, Suzuka will help astronomers understand the evolution of galaxies and the supermassive black holes at their centres.

How Much Material Was Blasted Off By Deep Impact?

By Fraser Cain - July 11, 2005 01:36 AM UTC | Planetary Science

One of the instruments tuned into Deep Impact is NASA's Swift satellite, normally designed to detect and analyze gamma ray bursts. Swift has been watching the expanding debris cloud, and detected increasing numbers of X-rays every day. This has enabled scientists to accurately measure the total amount of material released. So far, it appears that several tens of thousands of tonnes of debris were blasted off the comet into space; enough to bury a football field under 9 metres (30 feet) of dust.

Transit Method Turns Up Planets

By Fraser Cain - July 11, 2005 01:15 AM UTC | Exoplanets

Of the 130 extrasolar planets discovered to date, most have been found using the radial velocity method, where a planet causes tiny changes to a star's velocity compared to the Earth. This back and forth motion changes the wavelength of the light from our perspective. Another method, the transit method, has turned up 6 planets so far, and should find many more in the coming years. It works by watching for a star to dim slightly on a regular basis as a planet passes in between us and the star.

No, Mars Won't Look as Big as the Moon

By Fraser Cain - July 08, 2005 05:51 AM UTC | Planetary Science

There's a new rumour going around the Internet. Maybe an excited friend has sent an email about a once in a lifetime chance to see Mars. Mars is going to make its closest approach on October 30th, 2005, and look bigger and brighter than it has in two years. Unfortunately, the closest approach actually happened two years ago, in August 2003, when the Earth and Mars were closer than they had been for 50,000 years.