THIS SITE IS UPDATED OFTEN TO HELP YOU FIND YOUR WAY AROUND THE COSMOS.
The Hubble Space Telescope team released this composite image in honor of the Hubble Space Telescope’s 27th birthday and wrote: When the Hubble Space Telescope launched aboard the Space Shuttle Discovery on April 24, 1990, astronomers could only dream what they might see. Now, 27 years and more than a million observations later, the telescope delivers yet another magnificent view of the universe — this time, a striking pair of spiral galaxies much like our own Milky Way. These island cities of stars, which are approximately 55 million light-years away, give astronomers an idea of what our own galaxy would look like to an outside observer. The edge-on galaxy is called NGC 4302, and the tilted galaxy is NGC 4298. Although the pinwheel galaxies look quite different because they are angled at different positions on the sky, they are actually very similar in terms of their structure and contents.
The Pleiades – aka the Seven Sisters – captured by Greg Hogan in Kathleen, Georgia on October 31, 2016. The Pleiades star cluster – also known as the Seven Sisters or M45 – is visible from virtually every place that humanity inhabits Earth’s globe. It can be seen from as far north as the north pole, and farther south than the southernmost tip of South America. It looks like a tiny misty dipper of stars.
Mars seen by the Viking oriter. Image via NASA/JPL/USGS By Andrew Coates, UCL Europe has been trying to land on Mars since 2003, but none of the attempts have gone exactly according to plan. A couple of months ago, the ExoMars Schiaparelli landing demonstrator crashed onto the planet’s surface, losing contact with its mothership. However, the mission was partially successful, providing information that will enable Europe and Russia to land its ExoMars rover on the Red Planet in 2021. Now European research ministers have finally agreed to give the mission the outstanding €400m it needs to go ahead. A lot is at stake as the rover is poised to uniquely drill under the harsh Martian surface to search for signs of past, or even present, life. With the best of human endeavor, we must learn, try again and not give up. As leader of the international Panoramic Camera team on the rover, which will among other things provide surface geological and atmospheric context for the mission, I am one of many scientists working very hard to make it work. PanCam is one of nine state-of-the-art instruments which will help us analyze subsurface samples. The reason it is so hard to land on Mars is that the atmospheric pressure is low, less than 1% of Earth’s surface pressure. This means that any probe will descend very rapidly to the surface, and must be slowed. What’s more, the landing has to be done autonomously as the light travel time from Earth is three to 22 minutes. This delay transmission means we can’t steer the rapid process from Earth. NASA and Russia have had their own problems with landings in the past, before the spectacular successes with the US missions Viking, Pathfinder, Spirit,Opportunity, Phoenix and Curiosity
Our sun is located about two-thirds of the way out from the center of the Milky Way. Illustration via Caltech. The planets in our solar system orbit around the sun. One orbit of the Earth takes one year. Meanwhile, our entire solar system – our sun with its family of planets, moon, asteroid and comets – orbits the center of the Milky Way galaxy. Our sun and solar system move at about about 500,000 miles an hour (800,000 km/hr) in this huge orbit. So in 90 seconds, for example, we all move some 12,500 miles (20,000 km) in orbit around the galaxy’s center. Our Milky Way galaxy is a big place. Even at this blazing speed, it takes the sun approximately 225-250 million years to complete one journey around the galaxy’s center. This amount of time – the time it takes us to orbit the center of the galaxy – is sometimes called a cosmic year.
This artist’s concept puts solar system distances in perspective, but you have to think about it a bit to understand it. The scale bar is in astronomical units (AU), with each set distance beyond 1 AU representing 10 times the previous distance. One AU is the distance from the sun to the Earth, by the way, which is about 93 million miles or 150 million kilometers. Neptune, the most distant planet from the sun, is about 30 AU. Informally, the term solar system is often used to mean the space surrounding our sun, out to the last planet. Astronomers, however, might speak of the solar system as the heliosphere, or sphere of the sun’s influence. Our dominates its own region of space and creates a sort of bubble of charged particles in the space surrounding it. These particles are “blown” out from the sun by the solar wind. It’s this heliosphere that Voyager 1 has now left. NASA says Voyager 1 actually crossed the heliopause, the boundary around the region of the sun’s influence, over a year ago, on August 25, 2012. It’s also possible, though, to picture the solar system as going out to the Oort Cloud, the source of the comets that swing by our sun on long time scales. Beyond the outer edge of the Oort Cloud, the sun’s gravitational influence begins to wane. The inner edge of the main part of the Oort Cloud could be as close as 1,000 AU from our sun. The outer edge is estimated to be around 100,000 AU. So that’s 100,000 times the Earth-sun distance.