If you saw Comet Halley when the comet was 0.8 AU from Earth and you observed a visible tail 4 degrees long, how long was the tail in kilometers? (Hint: Use the small-angle formula.) (Note: 1 AU = 1.5 x 10° km.) x km

Astronomers are able to use techniques like measuring the Question Blank 1 of 2 (hint: two words) of a surface to determine the relative age of various parts of that surface. However, if they want a(n) Question Blank 2 of 2 (hint: one word) age of the surface, they need to collect surface samples and then radiometrically date them to get a more exact measurement.

Annual meteor showers occur when the Earth passes through the orbital path of acomet. The intensity of these showers vary from year to year. Which of the following may bethe reason for this? Group of answer choices - Meteor showers are not caused by comet debris - Sun's temperature - en distribution of debris along comet's orbit - Earth's rotation axis

Re-order the numbers so the events occur in the correct order, with the oldest event as number 2, and the youngest event as number 13. 2. Now at roughly 100% of present-day mass and the asteroid bombardment over, Earth begins cooling and differentiating. As the outer layer of the Earth cools and solidifies, lighter elements and compounds rise to the surface while the denser ones sink to the core 3. The now differentiated ice, gas, and dust of the solar accretion disc conglomerates together into asteroids from gravity 4. "The Big Whack" A Mars-sized protoplanet we call Theia collides with primitive Earth, adding even more energy and mass 5. The Big Bang 6. As the early atmosphere cools, water vapor is eventually cool enough to condense into liquid water, eventually covering the planet in an ocean 7. The debris from the collision of Earth and Theia produce a ring in orbit. This ring eventually coalesces into the Moon, just as Earth coalesced from the solar accretion disc 8. A nebula…