A Planet Made of Diamond!

 Artist's impression of the diamond planet

You read that right! Astronomers believe that they have discovered an exoplanet made of diamond! How can this happen? Well here's the scenario. There was once two stars orbiting each other in a binary system in our galaxy. One star was  bigger than other, and began stealing material from the other smaller star. Over time, the large star stripped so much material off the small star that it couldn't withstand the external pressure and exploded as a supernova! This huge explosion cleared away any gas and star material in the area, leaving behind only the core of the large star (now called a neutron star) and a the core of the small star. Because this is a binary system, the leftover cores began to orbit each other extremely quickly. The angular momentum in the system (speed of rotation, essentially) caused the neutron star to spin on its axis in a fraction of a second (once every 0.0057 seconds to be exact)! We call these stars pulsars, as they emit light from their poles which appears as mili-second pulses in radio telescopes. The small star's core now orbits the pulsar so closely that it only takes two hours for the planet to go around the star! Based on orbital speed and distance to the host star, astronomers speculate that it is less than half the size of Jupiter, but weighs about 1.2 times as much! This high density suggests that the star is made of carbon, and its close proximity to the host star would make it crystallized. And you know what crystallized carbon is… Diamond! A planet 5 times the size of Earth made diamond. I Think I agree with other astronomers who suggest that we somehow find a way to travel to this planet and bring some diamond back! (Though it's quite implausible.) Wouldn't it be awesome to have an exoplanet-diamond ring ? And I thought a meteorite necklace was cool!

Our Solar System

After some recent teaching experiences and discussions, I've come to realize that many adults have forgotten the basics about our solar system. So today ADYK presents a Solar System "refresher" to help you recall those astronomy facts you learned back in elementary school.

 

Above is a collection of real telescope images of the planets in our solar system (NOT to scale!). This is what the planets look like when you use very high power telescopes or planet orbiting satellites to observe them.

Our solar system contains 8 planets (Pluto doesn't count anymore),  one star (the Sun) and two large asteroid belts. Mercury, Venus, Earth and Mars and the four closest planets to the sun and are often called the terrestrial or rocky planets. They are basically giant chunks of rock in a roughly spherical shape. Mercury is made mostly of metals and is heavily cratered like the moon. Venus has a thick carbon dioxide atmosphere, and is essentially the poster child for what would happen if global warming got out of hand on earth. Earth is our home and is made of 70% salt water and has a rich Nitrogen atmosphere. Mars is the red planet where all the aliens live, supposedly. (*wink wink*). Beyond Mars sits the first asteroid belt, filled with oddly shaped rocks the size of people to the size of cities. Jupiter, Saturn, Uranus and Neptune sit beyond the asteroid belt and are often called the gaseous or Jovian planets. Jupiter is the largest planet, about 10x the size of Earth, and has that big red spot. Saturn is the one with the prominent ring structure, though all Jovian planets have a slight ring structure around them. Uranus and Neptune are the blue planets, and are about 4x the size of Earth. Uranus is turned on it's side, meaning that its spin axis is tilted 90 degrees from being straight "up and down". Past the Jovian planets is the Kuiper belt, a giant ring of asteroids which defines the edge of the solar system. Pluto, it's moons, and over 70,000 similar objects orbit in this ring. Most everything there is small, cold, and icy.

There you go, elementary school astronomy class in one paragraph!

Distance To The Stars

The stars are really far away, but how exactly do astronomers measure their distance? There are many different ways to measure the distance to an astronomical object, but for "nearby" stars, the easiest method is to use parallax. A stars parallax is a measurement of it's apparent position on the sky, related to very distant background stars, at two different positions in the Earth's orbit around the sun.

 

In the image above we have the Earth orbiting counterclockwise around the sun, a nearby star which we want to measure the distance to, and distant stars which appear stationary during the Earth's movement around the sun. When the Earth is to the left of the sun, the nearby star appears to be amongst distant stars on the right hand side. Six months later, the Earth is to the right of the sun, and the star appears amongst distant stars on the left. Half the apparent angular distance on the sky that the nearby star appeared to move is called parallax and is measured in arcseconds. Arcseconds are an angular measurement on the sky, defined such that a star that in one parsec (~19 trillion miles) away from Earth will have a parallax of 1 arcsecond. Using basic geometry, we find that the distance to any nearby star (in parsecs) is equivalent to 1/parallax (in arcseconds), or d=1/p. Just by using simple math that you probably learned in high school, you can calculate the distance to the stars. No calculus or crazy physics required! Now finding the distance to much more distant objects is a bit trickier, and will be the topic of future posts.

Image Credit: astroprofspage.com