Ganymede and Callisto are similar in size and are made of a similar mixture of ice and rock, but data from the Galileo and Voyager spacecraft show that they look different at the surface and on the inside. Just like Earth and Venus, Ganymede and Callisto are twins, and understanding how they were born the same and grew up to be so different is of tremendous interest to planetary scientists.
Ganymede and Callisto’s evolutionary paths diverged about 3.8 billion years ago during the Late Heavy Bombardment, the phase in lunar history dominated by large impact events. Impacts during this period melted Ganymede so thoroughly and deeply that the heat could not be quickly removed. All of Ganymede’s rock sank to its center the same way that all the chocolate chips sink to the bottom of a melted carton of ice cream. Callisto received fewer impacts at lower velocities and avoided complete melting. Ganymede is closer to Jupiter and therefore is hit by twice as many icy impactors as Callisto, and the impactors hitting Ganymede have a higher average velocity.
Image Credit: NOAA/GSD
Identification posters for bumblebees of the eastern and western United States. You can download printable pdf versions at the link.
Bringing this back since it’s spring.
(photo by nick athanas)
(photo by Chris Jimenez)
a little diamond dove pattern commissioned by tumblr user princeowl
i will probably make a post about commissioning patterns later but i know that ill only take a few at a time because of school and junk
Some recent Okami themed pottery. :3 Save for the first image, these will be in my Etsy store later! https://www.etsy.com/shop/midderin (currently empty)
EDIT: Thanks for the love guys! The items are live in my store! (though the Okamiden dish has sold) https://www.etsy.com/shop/midderin
The lovely Hoya Vine I have growing in my back yard <3 there’s always at least one cluster of buds at some different stage in the blooming process