Astrophysics

The outer layer of gas around the terrestrial or rocky planets is called the atmosphere, although Mercury's is so sparse that it is referred to an an exosphere (as if space began at its surface).

Star clusters provide a way to study the evolution of stars because they contain stars of different ages. By analyzing the attributes of stars in a cluster, astronomers can observe how they change over time, providing insights into the various stages of stellar evolution. Comparing the properties of stars within a cluster, such as their temperature, luminosity, and composition, allows astronomers to track their evolution from formation to eventual demise.

The name of the planet closest to our Sun is Mercury.

Cosmic Catch uses sensors to detect the colors of the band as you play the game. The sensors pick up on the specific color patterns as you move and interact with the game, allowing it to track your movements accurately.

The apparent passage of one celestial body across the disc of another one for an observer is called a transit. If the transiting body hides a significant portion of the one behind, it is called an occultation or eclipse.

The Van Allen radiation belts

No, it is not possible to stop cosmic ray showers. They are high-energy particles from outer space that constantly bombard Earth's atmosphere. However, Earth's atmosphere acts as a shield, absorbing and deflecting most of the cosmic rays before they reach the surface.

The outermost planet in our solar system, Neptune, is often referred to as the eighth planet. When Pluto was considered a planet (prior to 2006) during its orbit it would cross inside the orbit of Neptune making the latter the outermost planet.

The 3 dwarf planets in our solar system are Pluto, Eris, and Haumea.

Because about 98 percent of the mass of the entire Solar System is concentrated in the Sun, it has gravitational predominance and does the least relative movement - the planets and other objects orbiting around it.

Mercury, with almost no atmosphere, is also closest to the sun and has the largest range of temperatures between the side facing the sun and the side facing away - a difference of about 600 K.

A celestial body is considered circumpolar when it never sets below the horizon as observed from a specific location on Earth. This occurs if the body's declination is always above the observer's local latitude. In practical terms, circumpolar bodies can be seen rotating around the celestial pole without ever dipping below the horizon.

Main sequence stars best obey the mass-luminosity relation. This empirical relation states that there is a direct relationship between a star's mass and its luminosity. In general, the more massive a main sequence star is, the more luminous it will be.

Mercury is the only planet in our solar system that is less than 3000km in diameter, with a diameter of about 4879 km.

A black hole's energy is in the form of its mass and angular momentum, which contribute to its gravitational pull and ability to influence spacetime. This energy is so strong that not even light can escape it, leading to the creation of an event horizon.

In our solar system, the largest planet, Jupiter, is indeed also the heaviest, weighing in at about 317 times the mass of Earth. However, a larger planet isn't necessarily a heavier one - for example, Uranus is larger but less massive than Neptune.

Yes, Mercury does rotate about its own axis. However, its rotation is unique in that it is in a 3:2 spin-orbit resonance, meaning it rotates on its axis three times for every two orbits around the Sun.

There is no planet that moves upside down in relation to its orbit around its parent star. All planets in our solar system orbit the Sun in a consistent direction, with the northern hemisphere generally tilted toward the same direction that they are orbiting.

Although not harmful in small doses, x-rays and cosmic rays potentially can damage tissue or sensitive computer equipment; spacecraft and some ground-based electronics are specially hardened against them for this reason.

High energy particles have the potential to damage DNA and in some cases cause mutations, although this is not a cause for panic. The Earth's atmosphere and powerful magnetic field manage to shield us from most space-born radiation and high-energy particles.

In a typical year a person might receive about 360 millirems of x-ray radiation from space and other normal sources of radiation in the matter around us. By comparison, a dental x-ray is about 2 to 3 mrems. Astronauts which travel outside the Earth's magnetosphere were known to be exposed to larger doses of radiation; this was studied as part of the Apollo lunar mission effort, and the levels deemed safe owing to the brevity of the missions. Some astronauts reported seeing brief flashes of light in their vision, which was attributed to cosmic rays although the mechanism is not fully understood.

Black holes have a significant impact on the universe and the world indirectly. They can influence the movement of stars and galaxies, and their immense gravitational pull plays a role in shaping the structure of the universe. While they are not directly relevant to life on Earth, their existence helps us understand fundamental concepts in physics and the evolution of the cosmos.

Yes, some celestial bodies are composed partly or entirely of gas. Our Sun is largely hydrogen and helium, some other elements which are heavier are still in a gaseous state because of the high temperature. Most stars would fit that pattern.

In addition, some planets in our solar system have significant gaseous envelopes, the outer planets being an example although each are also believed to have a relatively small rocky (silicate) core.

Venus is the planet that receives more heat from the Sun than it is able to radiate back into space, making it the hottest planet in our solar system. This is due to its thick atmosphere composed mainly of carbon dioxide, which traps heat through the greenhouse effect.

The best estimate for July of 2007 was 6,602,224,175 (CIA Factbook).