Stories tagged Earth and Space Science

Oct
19
2006

Aurora borealis: over Edinburgh in 2004.Courtesy piglicker
Aurora borealis: over Edinburgh in 2004.
Courtesy piglicker

The aurora borealis, or Northern Lights, are caused by high-energy particles streaming from the Sun collide with molecules high in the Earth’s atmosphere. The Sun has been pretty active of late, and scientists at the Geophysical Institute of the University of Alaska Fairbanks are predicting another aurora peak for the night of the 19th, perhaps lasting through the night of the 20th. The aurora may be visible throughout Canada and the northern tier of states in the US, as well as Russia, Scandinavia, New Zealand and Tasmania.

Check their website for hourly forecasts , and for general information on auroras.

If you see the aurora, let us know! Post a comment with your location and the time you saw it (or didn’t see it), and we’ll try to produce an aurora map.

Oct
18
2006

Dry moon: Radar images taken from the moon's south pole have decreased the odds that ice, and therefore water, can be found on the moon's surface. Photo from NASA
Dry moon: Radar images taken from the moon's south pole have decreased the odds that ice, and therefore water, can be found on the moon's surface. Photo from NASA

New pictures from the moon are drying up any ideas that its poles might have traces of ice that could hold water for future manned trips there.

The high-resolution images, shared in the recent edition of the journal Nature, dispute the theory of cold traps on the poles, particularly the moon’s south pole, where water particles were thought to possibly be found as ice. Radar shots from Earth can now look into these cold traps, which are permanently shaded craters on the moon’s south pole.

Such ice deposits have been found on the planet mercury using the same radar measurement techniques. But the latest images showed no traces of ice on the portions of the moon that radar imaging was done on.

Researchers point out that it doesn’t mean there is no ice on the moon’s south pole, just on the areas that were tested. But the bad news, to anyone thinking of making a manned mission to the moon, is that there probably wouldn’t be enough iced water on the pole to help support a long mission.

Six years ago, the Lunar Prospector orbiter found concentrations of hydrogen around the lunar poles. If that hydrogen could be combined with oxygen in some fashion, estimates were that there could be up to a 1 or 2 percent mixture of ice in the soil on the moon’s poles.

So if you’re planning on going to the moon anytime soon, still plan on bringing enough water for everyone in your party.

Oct
07
2006

Victoria crater, Mars: credit: NASA/JPL/UA
Victoria crater, Mars: credit: NASA/JPL/UA

Springtime on Mars

Our two little Mars rover robots survived another winter on Mars. Spirit, who has a bad wheel, sat on a hillside facing the sun. Opportunity, who spent several weeks spinning its wheels in a sand dune, has now reached a huge crater named Victoria. Progress will be slow during October, though, because the Sun's position near our radio path causes interference.

Rovers goal is to find evidence of water

Within two months after landing on Mars in early 2004, Opportunity found geological evidence for a long-ago environment that was wet. Deeper sediments exposed in craters allow a look into Mar's past. The Eagle Crater, in which Opportunity landed in 2004, gave geologists about 0.5 metres of layered rock to study. Endurance Crater, where Opportunity spent about six months, provided 7 metres of layers. Victoria Crater appears to be at least 60 metres deep.

"This is a geologist's dream come true," says rover principal scientist Steve Squyres of Cornell University in Ithaca, New York, US. "Those layers of rock, if we can get to them, will tell us new stories about the environmental conditions long ago. New Scientist

Jim Bell of Cornell, lead scientist for the rovers' panoramic cameras says NASA plans to drive Opportunity from crater ridge to ridge, studying nearby cliffs across the intervening alcoves and looking for safe ways to drive the rover down.

"It's like going to the Grand Canyon and seeing what you can from several different overlooks before you walk down," Bell said.

Want see more

Oct
02
2006


Pine Barrens Tree Frog: In this image the tympanum can be seen as the small round disk to the right of the eye. Image courtesy Bruce Means and the U.S. Fish and Wildlife Service.
Do frogs have ears?

Yes, they do, but they are different from the ears we have. Frogs do not have external ears, rather they have something called a tympanum. The tympanum are behind the eyes, and look like round disks. Some tympanum are easier to see than others. They receive sound waves for the frog just like the tympanic membrane (also known as the eardrum) does for us. Frogs not only use the tympanum to hear, but also use their lungs. The lungs help with hearing, and also protect the frog’s eardrums from the very loud noises frogs make by equalizing pressures between the inner and outer surfaces of the tympanum.

What does sublimation mean?

In physics, sublimation is the process by which a solid converts to a gas and bypasses a liquid stage in doing so. Have you ever seen dry ice? At room temperature, dry ice sublimates directly into a gas, skipping the liquid stage.

Where do Komodo Dragons live?

There are about 6,000 Komodo Dragons living in the wild. They live on the Lesser Sunda Islands in Indonesia.

What causes hiccups?

There are a variety of causes for hiccups, including eating too quickly, swallowing too much air, taking a cold drink while eating a hot meal, laughing, coughing, or drinking too much alcohol.

Hiccups are an involuntary spasm of the diaphragm, the large muscle that separates the chest cavity from the abdominal cavity. The sudden intake of air into the lungs is stopped by the glottis, which causes the “hic” sound.

Do you know how fast the Earth spins on its axis?

Well, if you figure the Earth does one full rotation on its axis about every 24 hours (23 hours, 56 minutes, and 04.09 seconds), and the Earth’s circumference is around 25,000 miles (24,901.55 miles), then it spins at roughly 1,040 miles per hour.

Illustration of the life-cycle of the Sun: Illustration courtesy Tablizer.
Illustration of the life-cycle of the Sun: Illustration courtesy Tablizer.Courtesy Tablizer
Will the sun explode?

No, but one day it will be large enough to push the Earth into a new orbit while eradicating the Earth’s atmosphere – but not for a long, long time. Our sun does not have enough mass to “go supernova” and explode. But, in about 5-6 billion years it will start becoming a red giant once it has used up its supply of hydrogen in its core and switched to fusing hydrogen in a shell outside of its core. While this is happening other processes will cause the sun to grow. Much, much later, the red dwarf will become a planetary nebula, and then a white dwarf. This is the standard stellar evolution for a star such as our sun.

Sep
21
2006

Artist's concept of Eris.: Image courtsey NASA/JPL-Caltech.
Artist's concept of Eris.: Image courtsey NASA/JPL-Caltech.

The “Tenth Planet” that caused Pluto to lose its planetary status has been classified and named, and to the dismay of many, it was not named Xena. The International Astronomical Union has classified it as a dwarf planet and named it Eris, after the Greek goddess of Chaos, which is appropriate for the chaos it cause in the astronomical community over what should be defined a planet and what should not.

The debate centered around the argument that if Pluto was considered a planet, then 2003 UB313, as it was known at the time, should be a planet as well as it was larger than Pluto. The debate culminated at the International Astronomical Union meeting last month where Pluto was stripped of the title “planet” and relegated to “dwarf planet” along with Eris and the former asteroid Ceres.

Eris' moon was also given a formal name: Dysnomia. In Greek mythology Dysnomia was the daughter of Eris.

Sep
21
2006

Orion Launch: The Orion crew vehicle launches on board the Ares I launch vehicle.  Photo courtesy Lockheed Martin Corp.
Orion Launch: The Orion crew vehicle launches on board the Ares I launch vehicle. Photo courtesy Lockheed Martin Corp.

A new space capsule and launch system are being developed to bring the next generation of explorers to the International Space Station, back to the moon, and later to Mars. The new Orion space capsule and Ares launch system will be the long awaited replacement for the Space Shuttle and are scheduled to begin use by 2014.

A throw-back design

The Orion capsule borrows its design from the Apollo-era space capsules, and improves on the best features of Apollo and the Space Shuttle programs, but is significantly larger than the old Apollo spacecraft and utilizes the latest technology in computers, electronics, life support, safety, propulsion and heat protection systems.
Orion will be capable of transporting cargo and up to six crew members to and from the International Space Station. In addition, it will return humans to the moon to stay for long periods as NASA prepares for the longer journey to and an extended stay on Mars.

Orion in Lunar Orbit: Photo courtesy Lockheed Martin Corp.
Orion in Lunar Orbit: Photo courtesy Lockheed Martin Corp.

Safer manned space flight

The new capsule and launch system will be significantly safer than the Space Shuttle because the design allows for an “escape tower” at the top of the capsule that allows for the separation of the crew capsule from the rocket below in the event of an emergency during launch. Further, there is minimal chance of debris damage as the capsule sits on top of the rocket.

To watch a video about the Orion and Ares systems, go here.

Sep
16
2006

There's been a rash of cool weather sites written up in the Twin Cities newspapers and other media lately.

Here are just a few:

Skeetobiteweather is one of the most popular hurricane sites run by amateurs. Jonathon Grant, of Lakeland, Florida, runs it. He says the site gets 1.8 million page views a week, and you can plug in your zip code and get a prediction of wind forces for your block, hour-by-hour, before a hurricane hits. (Not even the National Weather Service does that.) And pretty soon, you'll be able to enter your exact address.

Mark Sudduth, of Wilmington, North Carolina, runs HurricaneTrack and HurricaneLiveNet. He deploys several battery-powered, waterproof cameras at the exact points where hurricanes are expected to hit. He also collects weather data to accompany the live, streaming video.

Jesse Bass, of Hampton Roads, Virginia, is a weather chaser who posts photos and commentary on his website, VAStormPhoto.

HurricaneCity, despite its name, is one of the more comprehensive severe weather sites. Jim Williams, of Delray Beach, Florida, focuses on the city being hit, and you can see all live, streaming radio stations or TV from the site. He also has a towercam on his roof, which captured images from Hurricane Wilma last year, and he hosts "The Hurricane Warning Show" from his living room.

Mike Watkins, of Coconut Creek, Florida, covers Atlantic hurricane action on TropicalUpdate. And if there's no news on the hurricane front, he hosts an Internet radio show where he interviews the "celebrities" of the weather world--guys like Max Mayfield, of the National Hurricane Center, or William Gray, the Colorado State University professor who's known for his hurricane season forecasts.

Sep
14
2006

Thursday, astronomers discovered a new planet so "puffy" that it would float in water. This new planet named HAT-P-1, is the largest and least dense planet found outside our solar system. 450 light-years from Earth, HAT-P-1 orbits a star in the constellation Lacerta. This planet is a gas giant, composed of hydrogen and helium. Robert Noyes, a research astrophysicist from the Smithsonian Astrophysical Observatory, claims HAT-P-1 would "float if placed in a cosmic glass of water." HAT-P-1 orbits its parent star at one-twentieth the distance that seperates Earth and the sun, taking only 4.5 days to orbit, versus our 365 days! HAT-P-1 was discovered by a network of telescopes in Hawaii and Arizona. It is too distant to be seen with the naked eye, but visible with binoculars.

Aug
26
2006

Sunspot numbers by year: Photo source GlobalWarmingArt
Sunspot numbers by year: Photo source GlobalWarmingArt

Magnetic reversal in sunspot 905 signals new sunspot cycle.

Sunspots go through an eleven year cycle. When one solar cycle gives way to another--sunspots reverse polarity. For the second time in a month, a backward sunspot has appeared. The first backward spot, sighted on July 31st, was tiny and fleeting. The latest, however, is big and sturdy, bipolar sunspot 905.

The onset of Solar Cycle 24 is big news, because the cycle is expected to be intense, but don't expect any big storms right away. Solar cycles take years to ramp up to full power. The next Solar Max is expected in 2010.SpaceWeather

Most intense solar maximum in fifty years is forcast.

The prediction comes from a team led by Mausumi Dikpati of the National Center for Atmospheric Research (NCAR).

"The next sunspot cycle will be 30% to 50% stronger than the previous one," she says.

If correct, the years ahead could produce a burst of solar activity second only to the historic Solar Max of 1958. During the intense solarspot activity of 1958 people knew something big was happening. Northern Lights were sighted three times in Mexico. A similar maximum now would be noticed by its effect on cell phones, GPS, weather satellites and many other modern technologies.
Solar physicist David Hathaway of the National Space Science & Technology Center (NSSTC) explains that a convection current "conveyor belt" cycles magnetic knots from the core of the sun up to the surface, then back toward the core again. The cycle varys from 30 to 50 years. If it is flowing fast we will get more sunspots appearing. [email protected]

Aug
22
2006

Dark Matter revealed: Credit: NASA/SAO/CXC/M.Markevitch et al.
Dark Matter revealed: Credit: NASA/SAO/CXC/M.Markevitch et al.

What the universe is made of

    70% - dark energy
    25% - dark matter
    5% - ordinary matter

In a recent collision of galaxies known as the Bullet Cluster, scientists think they have proof of dark matter. In this cluster there are galaxies and intermixed gasses. When there was a collision, the gasses slowed more than the galaxies. Measurements showed that large amounts of mass that that should have fallen behind with the gasses continued ahead with the galaxies.

"This provides the first direct proof that dark matter must exist and that it must make up the majority of the matter in the Universe." said study leader Doug Clowe, from the University of Arizona.

Proof of the invisible

Observations of our universe have not "fit" into our theories about how the universe should behave. To solve this dilemma, scientists "invented" what they call dark matter and dark energy. Dark matter refers to matter that does not emit or reflect enough electromagnetic radiation (light) to be detected directly, but whose presence may be inferred from its gravitational effects on visible matter. An example is when light from a known star is bent too much as it goes near a galaxy. The explanation is that the galaxy must have some invisible (dark) matter. Several other observable phenomena support that galaxies, clusters of galaxies, and the universe as a whole contain far more matter than is directly observable, indicating that the remainder is dark.

Alternative explanations

A second explanation is that gravity does not behave the same way in galaxy clusters light years in size as it does on Earth.
A proposed alternative to physical dark matter particles has been to suppose that the observed inconsistencies are due to an incomplete understanding of gravitation. To explain the observations, the gravitational force has to become stronger than the Newtonian approximation at great distances or in weak fields.

Source: NASA press release