The Hubble Ultra-Deep Field (HUDF) is an image of a small region of space in the constellation Fornax, containing an estimated 10,000 galaxies. The original release was combined from Hubble Space Telescope data accumulated over a period from September 24, 2003, through to January 16, 2004. Looking back approximately 13 billion years (between 400 and 800 million years after the Big Bang) it has been used to search for galaxies that existed at that time. The HUDF image was taken in a section of the sky with a low density of bright stars in the near-field, allowing much better viewing of dimmer, more distant objects. In August and September 2009, the HUDF field was observed at longer wavelengths (1. 0 to 1. 6 µm) using the infrared channel of the recently attached Wide Field Camera 3 (WFC3) instrument. When combined with existing HUDF data, astronomers were able to identify a new list of potentially very distant galaxies.
Had Jupiter continued to gain weight, it would have grown ever hotter and hotter, and ultimately self-sustaining, raging nuclear-fusing fires may have been ignited in its heart. This would have sent Jupiter down that long, shining stellar road to full-fledged stardom. Had this occurred, Jupiter and our Sun would have been binary stellar sisters, and we probably would not be here now to tell the story. Our planet, and its seven lovely sisters, as well as all of the moons and smaller objects dancing around our Star, would not have been able to form. However, Jupiter failed to reach stardom. After its brilliant, sparkling birth, it began to shrink. Today, Jupiter emits a mere.00001 as much radiation as our Sun, and its luminosity is only.0000001 that of our Star. There was a time when Earth had no Moon. About 4.5 billion years ago, when our ancient Solar System was still forming, the dark night sky above our primordial planet was moonless. At this time, the Earth was about 60 percent formed, although it did have a differentiated crust, mantle, and core. This was a very chaotic and violent era in our Solar System's past, with planets first forming out of blobs of primordial dust, gas, and rock. During this era, frequently likened to a "cosmic shooting gallery", collisions between the still-forming planets were commonplace. Orbits were not as orderly as they are now. The very productive Cassini mission might attain some indirect information by analyzing the ring arc material--however, it is unlikely to come close to the little moon again before the mission ends in 2017.