Stars, Meteorites & Space Physics

Which spectral class does the Sun belong to?

Correct answer: G2 V

The Sun is a G2 V star: G2 describes its spectral type and V means it is a main-sequence star, generating energy by fusing hydrogen in its core.

What is the term for a rocky object that survives passage through Earth's atmosphere and reaches the ground?

Correct answer: Meteorite

A meteoroid that survives its passage through the atmosphere and reaches the ground is called a meteorite. The bright streak seen as it heats and glows in the atmosphere is a meteor, not the rock after it lands.

Further reading: science.nasa.gov ↗

Which metal is liquid at typical room temperature?

Correct answer: Mercury

Mercury is liquid at typical room temperature. Gallium melts just above ordinary room temperature, so it can melt in a warm hand but is usually solid in a cool room.

Which process supplies most of the energy in a red giant after hydrogen in its core is exhausted but before helium ignition?

Correct answer: Hydrogen shell burning

Hydrogen fusion continues in a shell surrounding the inert helium core.

Which moon is the largest natural satellite of Uranus?

Correct answer: Titania

Titania is Uranus's largest moon. It is one of the planet's five major moons and has a surface marked by impact craters and large fault valleys.

Which NASA telescope launched in 1990 and orbits Earth?

Correct answer: Hubble Space Telescope

Hubble was launched in 1990 and orbits Earth, observing the universe above much of the atmospheric distortion that affects ground-based telescopes.

Which dwarf planet is the most massive known object in the asteroid belt?

Correct answer: Ceres

Ceres is the largest and most massive object in the main asteroid belt between Mars and Jupiter. It is classified as a dwarf planet and was the first dwarf planet visited by a spacecraft, NASA's Dawn mission.

Further reading: science.nasa.gov ↗

Which planet takes longer to complete one rotation on its axis than to complete one orbit around the Sun?

Correct answer: Venus

Venus rotates so slowly that one rotation takes about 243 Earth days, while one orbit around the Sun takes about 225 Earth days. Its rotation is also retrograde, opposite to the direction of most planets.

Further reading: science.nasa.gov ↗

Which moon of Saturn has a thick nitrogen-rich atmosphere?

Correct answer: Titan

Titan's atmosphere is dense and composed mainly of nitrogen, with methane and other compounds present in smaller amounts. It is the only moon known to have a dense atmosphere.

Which star is the nearest known star to the Sun?

Correct answer: Proxima Centauri

Proxima Centauri is the Sun's nearest stellar neighbour. It belongs to the Alpha Centauri triple system, together with Alpha Centauri A and B.