Вторник, 27 Септември 2016 20:45

Космически телескоп Хъбъл

Телескопът „Хъбъл“ е създаден като съвместен проект на НАСА и Европейската космическа агенция. Телескопът е една от четирите „големи обсерватории“ на НАСА заедно с гама-обсерваторията Комптън, рентгеновата обсерватория Чандра и космическия телескоп Спицър, всички изведени в околоземна орбита. Първоначално се е предвиждало извеждането на телескопа на орбита да стане през 1986 г., но заради катастрофата на „Чаланджър“ той е качен на орбита на 25 април 1990 г. от совалката „Дискавъри“. При направата на първите снимки с телескопа се вижда, те са неясни и причината е в дефект на оптичното огледало – по-плоско с 2 μm и така фокусът е неточен и оттам некачествени снимки.

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Astronomers using NASA's Hubble Space Telescope have imaged what may be water vapor plumes erupting off the surface of Jupiter's moon Europa. This finding bolsters other Hubble observations suggesting the icy moon erupts with high altitude water vapor plumes.

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Понеделник, 19 Септември 2016 12:00

The biggest atoms in the universe

On 30 December 2015, the science of chemistry officially got four new subjects. The International Union of Pure and Applied Chemistry (IUPAC) confirmed the discovery of four new chemical elements, all of which had been created in labs.

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Сряда, 30 Декември 2015 12:10

The idea that life began as clay crystals is 50 years old

A rock is the ultimate example of inanimate, dead matter. After all, it just sits there, and only moves if it is pushed. But what if some minerals are not as stone-dead as we thought? Chemist Graham Cairns-Smith has spent his entire scientific career pushing a simple, radical idea: life did not begin with fiddly organic molecules like DNA, but with simple crystals.

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Петък, 06 Декември 2013 15:20

Is our Universe just a simulation?

Are you real? What about me?

These used to be questions that only philosophers worried about. Scientists just got on with figuring out how the world is, and why. But some of the current best guesses about how the world is seem to leave the question hanging over science too.

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Петък, 06 Декември 2013 07:07

In 250 million years Earth might only one continent

Science calls it "Pangaea Proxima". You might prefer to call it the Next Big Thing. A supercontinent is on its way that incorporates all of Earth's major landmasses, meaning you could walk from Australia to Alaska, or Patagonia to Scandinavia. But it will be about 250 million years in the making.

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Сряда, 20 Ноември 2013 17:07

It took centuries, but we now know the size of the Universe

"Let us go rambling about the Universe." This is the invitation that American astronomer Harlow Shapley gave to an audience in Washington DC in 1920. He was taking part in the so-called Great Debate with fellow scientist Heber Curtis on the scale of the Universe.

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Понеделник, 11 Ноември 2013 08:42

The real reasons nothing can ever go faster than light

It was September 2011 and physicist Antonio Ereditato had just shocked the world. The announcement he had made promised to overturn our understanding of the Universe. If the data gathered by 160 scientists working on the OPERA project were correct, the unthinkable had been observed.

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Петък, 08 Ноември 2013 07:12

Why Earth often has two moons

The Moon is Earth's only permanent natural satellite, as well as the only celestial body besides Earth to have been visited by humans. It is the fifth largest natural satellite in the Solar System, and the largest among planetary satellites relative to the size of the planet that it orbits (its primary). It is the second-densest satellite among those whose densities are known (after Jupiter's satellite Io).

The Moon is thought to have formed approximately 4.5 billion years ago, not long after Earth. There are several hypotheses for its origin; the most widely accepted explanation is that the Moon formed from the debris left over after a giant impact between Earth and a Mars-sized body called Theia.

The Moon is in synchronous rotation with Earth, always showing the same face, with its near side marked by dark volcanic maria that fill the spaces between the bright ancient crustal highlands and the prominent impact craters. It is the second-brightest regularly visible celestial object in Earth's sky after the Sun, as measured by illuminance on Earth's surface. Its surface is actually dark (although it can appear a very bright white) with a reflectance just slightly higher than that of worn asphalt. Its prominence in the sky and its regular cycle of phases have made the Moon an important cultural influence since ancient times on language, calendars, art, and mythology.

The Moon's gravitational influence produces the ocean tides, body tides, and the slight lengthening of the day. The Moon's current orbital distance is about thirty times the diameter of Earth, with its apparent size in the sky almost the same as that of the Sun, resulting in the Moon covering the Sun nearly precisely in total solar eclipse. This matching of apparent visual size will not continue in the far future. The Moon's linear distance from Earth is currently increasing at a rate of 3.82 ± 0.07 centimetres (1.504 ± 0.028 in) per year, but this rate is not constant.

The Soviet Union's Luna programme was the first to reach the Moon with unmanned spacecraft in 1959; the United States' NASA Apollo program achieved the only manned missions to date, beginning with the first manned lunar orbiting mission by Apollo 8 in 1968, and six manned lunar landings between 1969 and 1972, with the first being Apollo 11. These missions returned over 380 kg (840 lb) of lunar rocks, which have been used to develop a geological understanding of the Moon's origin, the formation of its internal structure, and its subsequent history. After the Apollo 17 mission in 1972, the Moon has been visited only by unmanned spacecraft.

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Понеделник, 07 Октомври 2013 16:07

Why parallel universes might be real

Is our Universe one of many? The idea of parallel universes, once consigned to science fiction, is now becoming respectable among scientists – at least, among physicists, who have a tendency to push ideas to the limits of what is conceivable.

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