Answer:
ACROSS:
1. Chicxulub
4. Meteor
5. Points away from the sun
6. A very large asteroid impact 65 million years ago is thought to have contributed to the extinction of about 75 percent of marine and land animals on Earth at the time, including the dinosaurs.
7. Oxygen or Silicon
DOWN:
2. Halley
3. Comet
5. Asteroid
6. Ceres
Explanation:
For more explanation read the sentences below.
ACROSS:
1. The Chicxulub crater is an impact crater buried underneath the Yucatán Peninsula in Mexico. Its center is offshore near the communities of Chicxulub Puerto and Chicxulub Pueblo, after which the crater is named. It was formed when a large asteroid, about 10 kilometers in diameter, struck the Earth.
4. A meteor, sometimes called a shooting star or falling star, is actually a space rock that is crashing through Earth's atmosphere.
5. Comet tails point away from the Sun, regardless of the direction in which the comet is traveling. ... Gases escaping from the comet are ionized by the ultraviolet photons from the Sun. Once they are ionized, the solar wind carries them straight outward away from the Sun. These gases form the plasma tail.
6. Meteorite Impacts in History
A very large asteroid impact 65 million years ago is thought to have contributed to the extinction of about 75 percent of marine and land animals on Earth at the time, including the dinosaurs.
It created the 180-mile-wide (300-kilometer-wide) Chicxulub Crater on the Yucatan Peninsula.
7. They are made up of oxygen and silicon, the number one and number two most abundant elements in the Earth's crust. The metallic asteroids are composed of up to 80% iron and 20% a mixture of nickel, iridium, palladium, platinum, gold, magnesium and other precious metals such as osmium, ruthenium and rhodium.
DOWN:
2. Halley's Comet is arguably the most famous comet in history.
3. Comets are sometimes called dirty snowballs or "icy mudballs". They are a mixture of ices (both water and frozen gases) and dust that for some reason didn't get incorporated into planets when the solar system was formed.
5. The asteroid belt is a torus-shaped region in the Solar System, located roughly between the orbits of the planets Jupiter and Mars. It contains a great many solid, irregularly shaped bodies, of many sizes, but much smaller than planets, called asteroids or minor planets.
6. Ceres
Discovery of Asteroids
In 1801, while making a star map, Giuseppe Piazzi accidentally discovered a small object 1000 kilometers (600 miles) in diameter between the orbits of Mars and Jupiter. Piazzi named the object Ceres. It was the first asteroid to be discovered.
