Microwave Anisotropy Probe | SilverScorpio.Com

Planck spacecraft obtains first peek of big bang’s ‘afterglow’

September 19, 2009 By admin Leave a Comment

London, September 18 (ANI): European Space Agency’s (ESA’s) Planck spacecraft has obtained its first peek at the afterglow of the big bang, revealing it in unprecedented detail.

The ESA spacecraft was launched into space on May 14 this year. It is observing the glow of hot gas from just 380,000 years after the big bang, called the cosmic microwave background (CMB).

According to a report in New Scientist, the detailed properties of this background may contain hints of hidden extra dimensions or multiple universes, as well as providing clues to what caused a brief, early period of incredibly rapid cosmic expansion.

Planck began surveying the microwave background on August 13, a few weeks after reaching its planned perch 1.5 million kilometres from Earth at a point called L2 and cooling its detectors to within 0.1 degrees Celsius above absolute zero.

Now, the Planck team has released the probe’s first image, an observational strip covering about 5 per cent of the sky.

Slight variations in temperature from place to place in the early universe give the image its mottled appearance.

“With a few per cent of the data in, you can see it’s working well and delivering good stuff,” said team member George Efstathiou of the University of Cambridge.

Planck is expected to provide the most detailed all-sky map of the cosmic microwave background yet, improving on the best current map, obtained by NASA’s Wilkinson Microwave Anisotropy Probe (WMAP), which launched in 2001.

Planck’s detectors have more than 10 times the sensitivity of WMAP’s, and about 2.5 times the angular resolution.

“Every strip that Planck scans, we’re getting data that is many, many times more sensitive than WMAP,” Efstathiou told New Scientist.

Although Planck was only designed to observe the sky for 15 months, the team believes it could last for more than 30 months, based on new estimates of how long its coolant will last.

The extra time will allow Planck to measure the radiation with even greater precision, since it will scan the entire sky four times – two more than originally planned. (ANI)

Filed Under: Uncategorized Tagged With: absolute zero, afterglow, agency, angular, Angular Resolution, ANI, anisotropy, appearance, August, background, bang, big bang, cambridge, celsius, cent, CMB, coolant, Cosmic Expansion, cosmic microwave background, detail, early universe, Earth, ESA, European, european space agency, expansion, first image, Gas, George Efstathiou, glow, image, London, map, May, member, microwave, Microwave Anisotropy Probe, Multiple Universes, NASA, New, New Scientist, Observational, peek, perch, period, place, Planck, point, precision, probe, radiation, report, resolution, scientist, sensitivity, September, sky, Sky Map, slight, space, spacecraft, strip, stuff, team, temperature, time, universe, University, university of cambridge, Unprecedented Detail, wilkinson, Wilkinson Microwave Anisotropy, Wilkinson Microwave Anisotropy Probe, Wilkinson Microwave Anisotropy Probe Wmap, WMAP, year

Future astronauts may be sent to ‘gravity holes’

August 29, 2009 By admin Leave a Comment

London, August 29 (ANI): If scientists have their way, then space missions in the future might see astronauts being sent to ‘gravity holes’.

Gravitational “sweet spots” called Lagrange points lie at least 1 million kilometres away.

These points are great swathes of space where the gravitational acceleration from the Earth and the sun are exactly equal, letting objects stick there with very little effort.

Because they’re far from warm stars and planets, they make useful havens for ultra-cold telescopes that measure fluctuations in the temperature of deep space.

The Wilkinson Microwave Anisotropy Probe (WMAP), which measures radiation from the big bang, is located at a Lagrange point called L2 more than 1 million kilometres away.

The successor to the Hubble Space Telescope, the massive James Webb Space Telescope, will also be sent to the spot, which lies in line with the sun and Earth.

“If you look at our list of future space telescope concepts, just about all of them are going to go to L2,” said Dan Lester of the University of Texas, Austin. “That’s going to be a very busy place out there,” he added.

But what would humans do there?

According to a report in New Scientist, one useful task is repairing and upgrading the new telescopes, like astronauts have done five times with Hubble.

“If we want to have humans having anything to do with these new telescopes, we really have to think about Lagrange points,” Lester said.

Astronauts may not have to go as far as L2 to be useful.

Lagrange points exist in the Earth-moon system, and every other planet in the solar system also boasts Lagrange points with the sun.

It takes surprisingly little energy to travel between these points, because massive bodies like the sun and planets have gravitational fields that resemble mountains and hills, but Lagrange points are all at gravitational lowlands.

Once set on the right path, spacecraft can coast along the gravitational contours of space between these lowlands, as if travelling on an interplanetary superhighway.

“Going back and forth between Earth-sun Lagrange points and Earth-moon Lagrange points is pretty much a matter of giving the thing a swift kick,” Lester told New Scientist.

Future astronauts could repair telescopes at a staging area at the nearest Earth-moon Lagrange point and send them sailing back to L2 when they’re done.

They could also assemble large telescopes or spaceships at the staging area and then send them out to farther-flung destinations.(ANI)

Filed Under: Science News Tagged With: cold telescopes, earth moon, gravitational acceleration, Hubble Space Telescope, James Webb Space Telescope, lagrange point, massive bodies, measure fluctuations, Microwave Anisotropy Probe, Moon System, mountains and hills, New Scientist, Space Missions, Stars And Planets, telescope concepts, University Of Texas Austin, Webb Space Telescope, Wilkinson Microwave Anisotropy, Wilkinson Microwave Anisotropy Probe, Wilkinson Microwave Anisotropy Probe Wmap

The Universe is flat, but not entirely

May 19, 2009 By admin Leave a Comment

London, May 19 (ANI): In a move that is reminiscent of scientists rejecting the view held by many people in the medieval times that the Earth is flat, a team of researchers has dismissed the notion that the Universe is completely flat.

According to a report in New Scientist, when it comes to the universe, “flatness” refers to the fate of light beams traveling large distances parallel to each other.

If the universe is “flat”, the beams will always remain parallel. Matter, energy and dark energy all produce curvature in space-time, however.

If the universe’s space-time is positively curved, like the surface of a sphere, parallel beams would come together. In a negatively curved, saddle-shaped universe, parallel beams would diverge.

Thanks in part to the Wilkinson Microwave Anisotropy Probe (WMAP) satellite, which revealed the density of matter and dark energy in the early universe, most astronomers are confident that the universe is flat.

But, that view is now being questioned by Joseph Silk at the University of Oxford and colleagues, who say it’s possible that the WMAP observations have been misinterpreted.

In a research paper accepted for publication in Monthly Notices of the Royal Astronomical Society, they took data from WMAP and other cosmology experiments and analyzed it using Bayes’s theorem, which can be used to show how the certainty attached to a particular conclusion is affected by different starting assumptions.

Using modern astronomers’ assumptions, which presuppose a flat universe, they calculated the probability that the universe was in one of three states: flat, positively curved or negatively curved.

This produced a 98 per cent probability that the universe is indeed flat.

When they reran the calculation starting from a more open-minded position, however, the probability changed to 67 per cent, making a flat universe far less of a certainty than astronomers generally conclude.

“It’s a reasonable assumption that the universe isn’t entirely flat,” Silk said, adding that the calculation reveals how strongly astronomers’ prejudices can affect their conclusions.

“They’ve developed a statistically rigorous way of examining the question,” said David Spergel of Princeton University, the spokesman for WMAP.

According to Silk, astronomers need to achieve a 99.9999 per cent level of confidence on the flat universe, high enough that the case starts to look compelling no matter what the starting assumptions are.

It’s possible, however, that no measurements will ever be able to get to that level of accuracy. (ANI)

Filed Under: Science News Tagged With: accuracy, ANI, anisotropy, assumption, astronomical, Bayes, Calculation, case, cent, certainty, conclusion, confidence, cosmology, curvature, dark energy, David Spergel, density, Density Of Matter, early universe, Earth, energy, fate, Flat Universe, flatness, Joseph Silk, level, Light Beams, London, matter, May, medieval, medieval times, microwave, Microwave Anisotropy Probe, monthly, Monthly Notices Of The Royal Astronomical Society, move, New, New Scientist, Notices, notion, Oxford, paper, Parallel Beams, part, position, presuppose, princeton, probability, probe, publication, question, reminiscent, report, reran, Research, royal, Royal Astronomical Society, satellite, scientist, society, sphere, spokesman, starting, surface, team, theorem, three states, universe, University, university of oxford, view, way, wilkinson, Wilkinson Microwave Anisotropy, Wilkinson Microwave Anisotropy Probe, Wilkinson Microwave Anisotropy Probe Wmap, WMAP, Wmap Satellite

Planck spacecraft obtains first peek of big bang’s ‘afterglow’

Future astronauts may be sent to ‘gravity holes’

The Universe is flat, but not entirely

Search More News

Technology News

Ads