THIS SITE IS UPDATED OFTEN TO HELP YOU FIND YOUR WAY AROUND THE COSMOS.
It’s possible not only to see the International Space Station passing overhead, appearing as a “star” that crosses your night sky, but also – if you have the right equipment – to capture it photographically. John Nelson in Puget Sound, Washington did that on October 10, 2017. John wrote: I receive notifications from the NASA SpotTheStation website when the ISS will be passing overhead. Tonight was a very high pass at 78 degrees maximum height from west-northwest to east-southeast. Being that high meant it would be about the best photographic opportunity I was likely to get. We had a beautiful clear night. Ideal conditions. The ISS moves at 7.7 km/sec. It’s relatively easy to manually track but focusing can be tricky. On this night, it was the brightest object in the sky by far … for the three minutes that it was visible. Nikon D810, Sigma 150-600mm lens with Sigma 1.4x teleconverter mounted on a gimbled tripod. EXIF: 1/2000sec, F/9, ISO 1000 RAW images processed in lightroom to export as jpeg. Minor tweaks to lighting to bring out background stars. Thank you, John! Bottom line: International Space Station over Puget Sound, October, 2017.
The Double Cluster is also known as h and Chi Persei. It resides in the northern part of the constellation Perseus, quite close to the constellation Cassiopeia the Queen. If you have a dark sky and find Cassiopeia – which is easy, because the constellation has a distinctive M or W shape – be sure to look for Perseus, too. Then just scan with your binoculars between them. The Double Cluster – a breathtaking pair of clusters, each containing supergiant suns – will be there. Follow the links below to learn more
In countless studies, astronomers have used our home galaxy, the Milky Way, as the classic example of a normal or typical galaxy. But a new study suggests our Milky Way might not be typical. Early results from a survey of our Milky Way’s satellite galaxies – and of other small satellite galaxies orbiting eight other, distant galaxies – indicate that Milky Way satellites are unusually tranquil. The survey is called SAGA (Satellites Around Galactic Analogs). According to a September 20, 2017 statement from Yale, it has found that – although the satellites of other galaxies similar to our Milky Way are “actively pumping out new stars” – the Milky Way’s satellites are “mostly inert.” Several dozen smaller galaxy satellites orbit the Milky Way’s center. Astronomers have long found them useful in understanding the Milky Way itself. But why are the Milky Way’s satellite galaxies not producing as many new stars as other satellite galaxies we see, orbiting distant galaxies? Astronomers find this extremely bothersome, because models depicting what we know about the universe rely on galaxies behaving in a fashion similar to our Milky Way.
Artist’s concept of Cassini’s final plunge into Saturn. NASA’s Cassini spacecraft is on final approach to Saturn, following confirmation by mission navigators that it is on course to dive into the planet’s atmosphere on Friday, September 15, 2017. Cassini is ending its 13-year tour of the Saturn system with an intentional plunge into the planet to ensure Saturn’s moons – in particular Enceladus, with its subsurface ocean and signs of hydrothermal activity – remain pristine for future exploration. The spacecraft’s fateful dive is the final beat in the mission’s Grand Finale, 22 weekly dives, which began in late April, through the gap between Saturn and its rings. No spacecraft has ever ventured so close to the planet before. The mission’s final calculations predict loss of contact with the Cassini spacecraft will take place on September 15 at 7:55 a.m. EDT (11:55 UTC; translate to your time zone). Cassini will enter Saturn’s atmosphere approximately one minute earlier, at an altitude of about 1,190 miles (1,915 km) above the planet’s estimated cloud tops (the altitude where the air pressure is 1-bar, equivalent to sea level on Earth). For the next couple of days, as Saturn looms ever larger, Cassini expects to take a last look around the Saturn system, snapping a few final images of the planet, features in its rings, and the moons Enceladus and Titan. The final set of views from Cassini’s imaging cameras is scheduled to be taken and transmitted to Earth on Thursday, September 14. If all goes as planned, images will be posted to the Cassini mission website beginning around 11 p.m. EDT (03:00 UTC on September 15). The unprocessed images will be available at: https://saturn.jpl.nasa.gov/galleries/raw-images
Humanity’s farthest and longest-lived spacecraft, Voyager 1 and 2, achieve 40 years of operation and exploration this August and September. Despite their vast distance, they continue to communicate with NASA daily, still probing the final frontier. Their story has not only impacted generations of current and future scientists and engineers, but also Earth’s culture, including film, art and music. Each spacecraft carries a Golden Record of Earth sounds, pictures and messages. Since the spacecraft could last billions of years, these circular time capsules could one day be the only traces of human civilization.
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.
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.