Space questions

Salyut 1 (DOS-1) (Russian: Салют-1) was the first space station of any kind, launched into low Earth orbit by the Soviet Union on April 19, 1971.

The speed at which light propagates through transparent materials, such as glass or air, is less than c. However, this "slowing of the light" is only due to the fact of photos being absorbed and re-emitted after a slight delay between atoms. When a photon is emitted, it's speed is always c. In exotic materials like Bose–Einstein condensates near absolute zero, the effective speed of light may be only a few metres per second.

The first woman in space, Soviet cosmonaut Valentina Tereshkova, flew in 1963. Space flight programs were slow to employ women, and only began to include them from the 1980s. Most women in space have been United States citizens, with missions on the Space Shuttle and on the International Space Station.

The rings of Saturn are the planetary rings around the planet Saturn, which can be seen with a small telescope.The particles in the rings are made almost entirely of water ice, with just a small amount of dust and other chemicals. There are some gaps in the rings. The moon Pan causes the gap called the "Encke gap" in Saturn's A ring. The Cassini Division, discovered by Giovanni Domenico Cassini, is a gap between the A ring and the B ring. It is a product of orbital resonance.

Dark nebulae are clouds of dust which are simply blocking the light from whatever is behind. They are physically very similar to reflection nebulae; they look different only because of the geometry of the light source, the cloud and the Earth. Dark nebulae are also often seen in conjunction with reflection and emission nebulae. A typical diffuse nebula is a few hundred light-years across. (NGC 2264 shown; see also the Horsehead Nebula)

Coronal holes generally discharge solar wind at a speed about twice the average. The escaping solar wind is known to travel along open magnetic field lines that pass through the coronal hole area. Since coronal holes are regions in the Sun’s corona that have much lower densities and temperatures than most of the corona, these regions are very thin. This thinness contributes to the solar wind since particles within the chromosphere can more easily break through.

The Pinwheel Galaxy ( M101) is a face-on spiral galaxy distanced 21 million light-years away from Earth in the constellation Ursa Major. M101 is a large galaxy, with a diameter of 170,000 light-years. By comparison, the Milky Way has a diameter of 258,000 light years. It has around a trillion stars, twice the number in the Milky Way. It has a disk mass on the order of 100 billion solar masses, along with a small central bulge of about 3 billion solar masses.

Henry Cavendish, british physicist (1731-1810) was the first scientist to calculate mass of the Earth. Greater accuracy has not been achieved for nearly 100 years. He only made a mistake about 1% compared to today's calculations. Cavendish estimated the mass of the Earth to be 6 billion trillion tons. Modern calculations say about 5.9725 billion trillion tons. (5,97219×10^24 kg)

Pluto, our tiny intrasolar neighbor, has a surface area of only a scant 6.45 million square miles. That might seem like quite a few square miles to sling around, but by comparison, that’s only one-third of one percent of the Earth’s total surface and small enough to fit entirely within the borders of Russia (6.6 million square miles). Pluto is a dwarf planet in the Kuiper belt, a ring of bodies beyond Neptune. It was the first Kuiper belt object to be discovered and is the largest known plutoid (or ice dwarf).

The James Webb Space Telescope is a space telescope that will be the successor to the Hubble Space Telescope.The JWST will provide greatly improved resolution and sensitivity over the Hubble, and will enable a broad range of investigations across the fields of astronomy and cosmology. The JWST's primary mirror is composed of 18 hexagonal mirror segments made of gold-coated beryllium. These combine to create a 6.5-meter (21 ft 4 in) diameter mirror that is much larger than the Hubble's 2.4-meter (7 ft 10 in) mirror.