It's true I'm a sucker
“Composed of 99.9% water-ice, the ring system has thousands of thin gaps, and was thicker and more varied in the past. The once-rocky material has coalesced into moons, but the watery rings will remain for as long as our Solar System exists.”
In the 1600s, the earliest telescopes saw that Saturn had “ears,” while later observers all the way back then finally saw their true nature: a ringed system with complex gaps, bands and colorations throughout. Since then, Saturn’s rings have been a source of wonder and puzzlement to skywatchers everywhere. The only ring system visible through most telescopes from Earth, Saturn’s main rings measure more than 70,000 km long, yet are no more than 1 km in thickness. Once thought to have only two gaps in them, the Cassini spacecraft has revealed over a thousand, teaching us that Saturn’s rings are ancient – likely as old as the planet itself – and will likely continue to exist for as long as our Sun shines.
Go get the full story in a glorious set of pictures from Cassini and no more than 200 words on today’s Mostly Mute Monday!
Earth, our home planet, is the fifth largest planet in our solar system and the only planet we know of where life exists. Even though Earth seems extremely large to us, it is actually a tiny spec in the vast expanse of the universe. Here are 7 space facts that will make you feel very small.
1. Our sun is one of at least 100 BILLION stars, just in the Milky Way. Scientists calculate that there are at least 100 billion galaxies in the observable universe, each one brimming with stars. There are more stars than grains of sand on all of Earth’s beaches combined.
In 1995, the first planet beyond our solar system was discovered. Now, thousands of planets orbiting sun-like stars have been discovered, also known as exoplanets.
2. The Milky Way is a huge city of stars, so big that even at the speed of light (which is fast!), it would take 100,000 years to travel across it.
3. Roughly 70% of the universe is made of dark energy. Dark matter makes up about 25%. The rest — everything on Earth, everything ever observed with all of our instruments, all normal matter adds up to less than 5% of the universe.
4. If the sun were as tall as a typical front door, Earth would be the size of a nickel.
5. The sun accounts for almost all of the mass in our solar system. Leaving .2% for all the planets and everything else.
6. Edwin Hubble discovered that the Universe is expanding and that at one point in time (14 billion years ago) the universe was all collected in just one point of space.
7. Four American spacecraft are headed out of our solar system to what scientists call interstellar space. Voyager 1 is the farthest out — more than 11 billion miles from our sun. It was the first manmade object to leave our solar system. Voyager 2, is speeding along at more than 39,000 mph, but will still take more than 296,000 years to pass Sirius, the brightest star in our night sky.
Feeling small yet? Here’s a tool that will show you just how tiny we are compared to everything else out there: http://imagine.gsfc.nasa.gov/features/cosmic/earth.html
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com
Astronomy compels the soul to look upward, and leads us from this world to another
Plato (via back-to-the-stars-again)
Tiggghhhttt
In March, Jupiter, it’s moons and moon shadows will all be visible in the sky. Find out when and where to look up:
Jupiter dominates the evening sky this month, rising at sunset and setting at dawn. On March 8, Jupiter reaches what is called “opposition”. Imagine that Jupiter and the sun are at opposite ends of a straight line, with the Earth in between. This brings Jupiter its closest to Earth, so it shines brighter and appears larger in telescopes.
On the nights of March 14 – 15, March 21 – 22 and March 29, two of Jupiter’s moons will cross the planet’s disk.
When the planet is at opposition and the sun shines on Jupiter’s moons, we can see the moon’s shadow crossing the planet. There are actually 11 of these double shadow transits in March!
The next six months will be awesome times for you to image Jupiter when it’s highest in the sky; near midnight now, and a little earlier each night through the late summer.
Even through the smallest telescopes or binoculars, you should be able to see the two prominent belts on each side of Jupiter’s equator made up of the four Galilean moons: Io, Europa Ganymede and Calisto. If you have a good enough view, you may even see Jupiter’s Red Spot!
Our Juno spacecraft will arrive at Jupiter on July 4th of this year and will go into orbit around the giant planet. Right now, the Juno mission science team is actively seeking amateur and professional images of the planet. These images are uploaded to a Juno website, and the public is invited to discuss points of interest in Jupiter’s atmosphere.
Locations will later be voted on and the favorites will be targets for JunoCam, the spacecraft’s imaging camera. Once JunoCam has taken the images, they’ll be posted online. Imaging participants can then process these raw mission images and re-upload them for others to view.
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com
Just a socially awkward college student with an interest in the celestial bodies in our universe.
279 posts