Podcaster: Richard Drumm
Title: Space Scoop: Snow White and the Five Dwarves
Organization: 365 Days Of Astronomy
Link : astrosphere.org ; http://unawe.org/kids/unawe1608/
Description: Space scoop, news for children.
Bio: Richard Drumm is President of the Charlottesville Astronomical Society and President of 3D – Drumm Digital Design, a video production company with clients such as Kodak, Xerox and GlaxoSmithKline Pharmaceuticals. He was an observer with the UVa Parallax Program at McCormick Observatory in 1981 & 1982. He has found that his greatest passion in life is public outreach astronomy and he pursues it at every opportunity.
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Transcript:
This is 365 Days of Astronomy. Today we bring you a new episode in our Space Scoop series. This show is produced in collaboration with Universe Awareness, a program that strives to inspire every child with our wonderful cosmos.
Today’s story is:
Snow White and the Five Dwarves
Have you heard the tale of Snow White and the Seven Dwarves? Well, our Sun has a collection of dwarves, too — five dwarf planets. Their names are: Ceres, Eris, Makemake, Haumea and Pluto. I’m sure that we’ll have 7 dwarves at some point just like Snow White.
Four of these dwarf planets lie in the cold outer part of the Solar System, beyond Neptune.
The fifth dwarf planet, though, lies in between Mars and Jupiter, in a region known as the ‘asteroid belt’ because it’s packed full of asteroids.
Well, it’s not all that full. There’s lots of empty space in this belt. The standard science fiction trope of a hyper-crowded asteroid belt where you have to steer your spaceship through them is just plain wrong.
This 5th dwarf planet is called Ceres and you can see a close-up photograph of it in our album artwork for this episode.
The crater you see there is named Occator, after the Roman god of that name. He’s the god of the harrow, the agricultural tool, and one of the 12 helper gods of the goddess Ceres, the god of the harvest. We get the word cereal from her name.
Do you see the white patches on Ceres’s surface that look like snow? There are over 130 of them all over Ceres, mostly associated with impact craters. The brightest of them are these in Occator crater.
These bright spots have puzzled scientists for a few years. In 2003 the Hubble space telescope could see a bright spot on Ceres as well, so this one has been known about for around 13 years.
In 2007 NASA sent a spacecraft called DAWN to take a closer look. The DAWN mission first visited the asteroid Vesta and returned spectacular images of that little world.
We at CosmoQuest have been counting craters on Vesta for a while and would like your help! Go to https://cosmoquest.org/ and join in the fun!
DAWN arrived at Ceres last year, 2015, and has been slowly lowering its orbit for almost a year. As of the middle of December 2015 it got as close as it’s going to get, 375 km, or about 230 miles from the surface.
Among other things, it’s examining the snow-white patches, which appear to contain magnesium sulfate hexahydrite, a relative of Epsom Salts.
But the salty spots are changing! Changing on daily and monthly time scales, too!
A team of Italian astronomers using the HARPS spectrograph on the ESO’s La Silla Observatory 3.6 meter telescope in Chile has detected numerous variations in the light coming from Ceres.
It looks like each day the strange white material evaporates in the sunlight, like a puddle of water in a desert, and disappears. Then comes the most exciting part – the material somehow reappears. But how?
One major possibility is that something must be happening underneath the surface, to push fresh new material out. In addition it may be that gasses given off in the daytime freeze out onto the surface at night and reappear that way as frost or snow.
Hazes of gas have been seen in Occator crater by the Dawn spacecraft. The hazes are densest at local noon, suggesting that they are created through the morning as the sunlight gets stronger. The hazes dissipate by local sundown.
The Herschel space observatory observed water vapor at Ceres in 2014. This may be the hazes Dawn has seen. Or it may not, time and more observations will tell and the Dawn spacecraft is in the best position to make the observations.
Ceres already has more in common with Earth than its rocky asteroid belt neighbors: scientists believe that the dwarf planet might contain even more fresh water than Earth! Although unlike Earth’s water, water on Ceres would be in the form of salty ice hidden deep under the surface.
This destroys another standard science fiction trope where aliens come to Earth to steal water when in reality water is abundant in the solar system and easier to get to in many other places than Earth.
Ceres, Europa, Enceladus, comets, the Kuiper Belt, the Oort Cloud! You want water? Go there for it. Leave Earth alone!
Heh, heh.
If the dwarf planet really is active under its surface, this will be yet another thing that sets it apart from its asteroid neighbors. Keep listening to 365 Days of Astronomy and our parent podcast Astronomy Cast as we investigate further!
Hey, Here’s A Cool Fact:
When it was first discovered, Ceres was classed as a planet. But it was eventually demoted to an asteroid and then upgraded to a dwarf planet. The number of planets in our Solar System has changed many times over the years. Maybe we’ll find Planet 9 soon!
Here’s a fun website that lets you explore how many planets there were at different dates: cosmos-book.github.io/how-many-planets/index.html I’ll put this link in the show notes for today’s episode.
On that website, slide the little slider button almost all the way to the right. In 2006 the category “Dwarf planet” is created and Ceres is upgraded and Eris, Makemake, Haumea and Pluto are recategorized. One of these recategorizations makes everybody go nuts. Just one.
[Sigh]
Thank you for listening to 365 Days of Astronomy!
End of podcast:
365 Days of Astronomy
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The 365 Days of Astronomy Podcast is produced by Astrosphere New Media. Audio post-production by Richard Drumm. Bandwidth donated by libsyn.com and wizzard media. You may reproduce and distribute this audio for non-commercial purposes. Please consider supporting the podcast with a few dollars (or Euros!). Visit us on the web at 365DaysOfAstronomy.org or email us at info@365DaysOfAstronomy.org. This year we will celebrate more discoveries and stories from the universe. Join us and share your story. Until tomorrow! Goodbye!