Asteroids & Impact 2010

What is an asteroid? Small, rocky object orbiting the Sun among other planets. Commonly called planetoids because they are considerably smaller than actual planets. Estimated amount of asteroids in our solar system –1,000,000 total

What are asteroids made of and how big are they? Fe and Ni Vary in size and shape, but can be up to 940 miles in diameter.

Who was the first to discover one? Father Giuseppi Piazzi Ceres, largest asteroid (940 km dia.) and first to be discovered. Discovered on January 1, 1801 *Discoverers name their asteroids

Ceres: size comparison

What are some cool asteroids? Vesta- the brightest asteroid Ceres- largest Ida- potato shaped and has a moon named Dactyl Pholus-covered in red, possibly organic, material Trojan Asteroids- orbit Jupiter, one group in front, one group behind

Ida (35X15 miles) and Dactyl

Are there different types of asteroids? Metal or M-class Similar to a core of a planet; made up of 5- 50% Ni and Fe.

Types…2 S-class: silica/Stony-Iron Metal/igneous rock; similar to mantle of a planet Two types: medosiderite and pallasite Pallasite has olivine crystals

Types…3 C-class: carbon Similar to crust of a planet; made of sand with Fe-Ni bits; grains are in irregular lumps called chondrules Achondrite: a chondrite that’s been reheated and lacks chondrules

Identify this asteroid:

Where can asteroids be found? Between Mars and Jupiter in the Asteroid Belt.

Radar image of view from 4179 Toutatis (travels 70,000 mph, often crosses Earth’s path)

How was the belt found? Johann Bode and Johann Titus determined a law giving the approximate distance of the planets from the Sun in Not a true law of relationships Pattern was used to find a planet between Mars and Jupiter, but found the asteroid belt.

What are Apollo Objects/NEO’s/PHA’s? Apollo Objects- about 40, all cross Earth’s orbit & have very elliptical orbits. Near Earth Objects- about 2,000 total which are greater than 1km in diameter PHA’s-Potentially Hazardous Asteroids *Concerned about these impacting Earth

NEO Orbits

Trojan Asteroids orbit with Jupiter (in green color)

“The blue area shows all near-Earth asteroids while the red area shows only large near-Earth asteroids. In this context, "large" is defined as an asteroid having an absolute magnitude (H) of 18.0 or brighter which roughly corresponds to diameters of 1 km or larger.”

Can I discover an asteroid? Unless you have access to the Hubble Telescope, LINEAR, Arecibo Radio Telescope, or an extremely expensive telescope of your own, your chances are slim.

What is LINEAR? LINEAR- Lincoln Near Earth Asteroid Research Project Detects asteroids; has ability to monitor and calculate future asteroid paths Helpful in case Earth might have to deflect any asteroids on a collision path

What is the Arecibo Radio Telescope? Radio telescope Uses radar to determine asteroid sizes, shapes and orbits Detect future impacts Can also map planets in our solar system

Arecibo Radio Telescope, PR

Is there a chance of future impact? There are numerous possibilities, but so far most of the NEO’s have come close enough without getting into Earth’s orbit If a large one were to enter Earth’s orbit, it would look like …

…this!

Or this!

How about this?

Any recent encounters? March 2002, 60 meter diameter asteroid came within 288,000 miles of Earth Wasn’t detected until 4 days later because it was coming from the direction of our Sun. June 2002, a 100-meter asteroid (2002MN) came within 75,000 miles—once again, undetected until 3 days later *largest asteroid to approach that close

Spaceguard Survey The term is from an Arthur C. Clarke novel The goal is to discover 90% of the Near Earth Objects that are 1km diameter or more. Global efforts being made Deflection strategies also being planned

Interesting facts Every asteroid in the Asteroid Belt put together would amount to less mass than Earth’s Moon Vesta can be seen with the naked eye NEAR Shoemaker landed on asteroid Eros, after orbiting for a year