Science and Space

space and astronomy articles.

Effect of global warming in space

While carbon dioxide is contributing a global rise in temperature at the Earth’s surface, it has the opposite effect in the thermosphere, upper part of the atmosphere, causing rapid decrease in temperature and the atmospheric density.

At first glance, this is good news for satellite operators: it will take longer for their satellites to re-enter the atmosphere.

However, the research conducted at the University of Southampton in collaboration with QinetiQ shows that in the later half of this century satellites would be at greater risk from collisions with orbiting debris since the amount of space debris orbiting the Earth will increase considerably.

According to the research team’s initial predictions a process known as ‘collision cascading’ - where the number of collisions in orbit increases exponentially - could occur much more quickly in the region of space between 200 km and 2,000 km above the Earth in response to rising CO2 levels. Simulations of a ‘business as usual’ scenario, where satellites are launched and destroyed at the rate they are now, show a 17 per cent increase in the number of collisions and a 30 per cent increase in the number of objects larger than 1cm by the end of the 21st century.

Source: universe.com

posted by: kyawoo at 21:37 | link | comments |
space science

Exoplanets

An extrasolar planet (or exoplanet) is a planet which orbits a star other than the Sun, and therefore belongs to a planetary system other than our solar system.

The first extrasolar planet around a main sequence star was discovered in 1995. Since then about 150 exoplanets have been detected. The detections are possible thanks to improved telescope technology, along with the Hubble Space Telescope. Such advances allowed for more accurate measurements of stellar motion, allowing astronomers to detect planets, not visually (the luminosity of a planet being too low for such detection), but by measuring gravitational influences upon stars. In addition, extrasolar planets can be detected by measuring the variance in a star’s apparent luminosity, as a planet passes in front of it.

Most of the planets found are of relatively high mass (at least 40 times that of the Earth); however, a couple seem to be approximately the size of the Earth.

On 2 May 2005, European scientists claimed they have for the first time taken a picture of a planet in another solar system. The exoplanet, is five times bigger and 10 times hotter than the biggest planet in our solar system, Jupiter. The photograph was taken last year by astronomers working with the Very Large Telescope at Mount Paranaol in Chile, the French National Scientific Research Center (CNRS) and the European Southern Observatory (ESO) said.

The exoplanet is twice as far from its sun as Neptune is from the Earth’s sun.

posted by: kyawoo at 11:48 | link | comments |
planets

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