lackyblue:
(by Thomas Shahan)
Emily Lakdawalla of the Planetary Society filed a report on humanity’s current roster of spacecraft currently exploring the solar system (and beyond).
Chang'e-4 and Yutu-2 are now past their prime mission and are in their extended mission phases. Their companion SmallSat, Longjiang-2, will crash into the Moon on 31 July to bring its mission to an intentional end. Parker Solar Probe is near aphelion as of 1 July and will reach its third death-defying solar perihelion on 1 September. BepiColombo completed its near-Earth commissioning phase on 5 April and is now settling into its long-cruise phase. Earlier this year, the ESA-JAXA Mercury mission was racing ahead of Earth on an inside track, but its elliptical orbit has now taken it farther from the Sun than Earth, allowing Earth to catch up. It will return to Earth’s neighborhood in April 2020 for a flyby.
I counted roughly 30 different probes and rovers in operation, most of them gathered around the Moon and Mars. Sure, where’s my jetpack and flying car and all that, but the fact that humanity has more than two dozen robots currently exploring the solar system seems pretty futuristic to me.
Wikipedia also has a page listing currently active probes and of course there’s the lovely & informative spaceprob.es as well.
March 20 marks the spring equinox. It’s the first day of astronomical spring in the Northern Hemisphere, and one of two days a year when day and night are just about equal lengths across the globe.
Because Earth is tilted on its axis, there are only two days a year when the sun shines down exactly over the equator, and the day/night line – called the terminator – runs straight from north to south.
In the Northern Hemisphere, the March equinox marks the beginning of spring – meaning that our half of Earth is slowly tilting towards the sun, giving us longer days and more sunlight, and moving us out of winter and into spring and summer.
An equinox is the product of celestial geometry, and there’s another big celestial event coming up later this year: a total solar eclipse.
A solar eclipse happens when the moon blocks our view of the sun. This can only happen at a new moon, the period about once each month when the moon’s orbit positions it between the sun and Earth — but solar eclipses don’t happen every month.
The moon’s orbit around Earth is inclined, so, from Earth’s view, on most months we see the moon passing above or below the sun. A solar eclipse happens only on those new moons where the alignment of all three bodies are in a perfectly straight line.
On Aug. 21, 2017, a total solar eclipse will be visible in the US along a narrow, 70-mile-wide path that runs from Oregon to South Carolina. Throughout the rest of North America – and even in parts of South America, Africa, Europe and Asia – the moon will partially obscure the sun.
Within the path of totality, the moon will completely cover the sun’s overwhelmingly bright face, revealing the relatively faint outer atmosphere, called the corona, for seconds or minutes, depending on location.
It’s essential to observe eye safety during an eclipse. Though it’s safe to look at the eclipse ONLY during the brief seconds of totality, you must use a proper solar filter or indirect viewing method when any part of the sun’s surface is exposed – whether during the partial phases of an eclipse, or just on a regular day.
Learn more about the August eclipse at eclipse2017.nasa.gov.
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com
All the planets in the solar system would fit between the Earth and the Moon
The South Pole, Jupiter
Jennifer Daniel
Was 2015 the year of Pluto? Or does its exit from the Eurozone make Greece Place of the Year? Now is the time to vote and tell us which place made the most history this year.
In the meantime, reflect on 2014 Place of the Year, Scotland.
Image: Public Domain via Wikimedia Commons.
The last shuttle
Space Shuttle Endeavour mounted atop one of NASA’s modified Boeing 747 Shuttle Carrier Aircraft.