Moon crossing the face of Earth will leave you spellbound
Wednesday, August 5, 2015, 1:03 PM - What's Up In Space? The far side of the moon cross the face of the Earth, NASA's Curiosity rover celebrates the third anniversary of its remarkable landing, and Philae gives us a view of a comet from just 9 metres away!
DSCOVR watches an unfamiliar face pass in front of the Earth
NOAA's Deep Space Climate Observatory has been in position at Lagrange Point 1 (L1) - between the Earth and the Sun - for nearly two months now, and it has provided us with some truly EPIC (Earth Polychromatic Imaging Camera) views of our world. Now, the NASA camera has captured a new sequence that's unlike anything we've seen outside of science fiction and computer simulations.
A sequence of images shot between 3:50 p.m. and 8:45 p.m. EDT on July 16, during the New Moon, shows the near-fully-lit far side of the moon passing across the face of the Earth. Credits: NASA/NOAA
If the sequence doesn't look quite real, it's understandable. After all, it's not often that we see the far side of the Moon, let alone nearly fully lit. The view of the Moon we're more familiar with has the famous "Man in the Moon" (or Wilma Flintstone, if you look carefully) and Tycho Crater, two easily distinguishable features. The far side of the Moon, on the other hand, is almost completely foreign to us.
Furthermore, seeing both the Earth and the Moon together in the same shot like this reveals just how much Earth's atmosphere affects light being reflected and emitted from the planet. The "pure" sunlight being reflected directly off the surface of the nearly-airless Moon and the "diffused" light coming off the Earth almost makes it look like the two were shot under different lighting.
From DSCOVR's vantage point, however - at a position roughly 1.6 million kilometres away, directly between the Earth and the Sun - this is the satellite's best view of a nearly Full Moon. "Nearly" is the best word to use here, since the satellite is not always perfectly centered between the Earth and the Sun (it will tend to 'wander' off of L1 from time to time). Thus, at times, it catches some of the shadow of the far side - as seen very clearly on the right edge of the Moon and more diffusely on the same edge of the Earth, in the images above.
The camera will image our more familiar sight of the Full Moon from time to time, however chances are greater that its view of that will be blocked by the planet.
Why doesn't the Moon's shadow pass across the Earth's face as well?
Since the Moon's orbit is tilted by a little over 5 degrees with respect to the Earth's orbit around the Sun, the Moon's shadow, more often than not, completely misses the Earth's surface during a New Moon. It's only when everything lines up perfectly that we get a solar eclipse.
Three years of amazing Martian science
On August 5, 2012, the Space Flight Operations Facility at NASA's Jet Propulsion Laboratory was abuzz with activity as one of the latest missions - the Mars Science Laboratory, aka "Curiosity" - approached the Red Planet. Bound for a crater in the southern equatorial region of Mars, Curiosity was about to execute a landing sequence that had never been tried before, and as if that wasn't stressful enough for the team back on Earth, they would have to endure a harrowing "seven minutes of terror," thanks to the time delay between Mars and Earth.
WATCH BELOW: Relive the "Seven Minutes of Terror" as NASA's Mars Curiosity rover plunges into the Martian atmosphere.
After the incredible success of the landing, Curiosity has gone on to make some amazing new discoveries about Mars, revamping our idea of what ancient Mars looked like and even confirming that the environment would have supported any life that managed to develop in that distant past.
WATCH BELOW: Curiosity Project Scientist Ashwin Vasavada delivers a special Third Anniversary Curiosity Rover Report.
Curiosity's goal is to reach the summit of Aeolis Mons (aka "Mount Sharp"), and study the different layers of rock and dirt on the way up, to see how Mars' environment changed over time. Given its incredible discoveries so far, and even more amazing revelations about the Red Planet may be in store for us soon.
Philae lander shows us Comet 67P from just metres away
On its way down to Comet 67P/Churyumov-Gerasimenko, before its first bounce off the surface, Rosetta's Philae lander took numerous pictures of its descent with the ROsetta Lander Imaging System (ROLIS). Those images arrived back here on Earth shortly thereafter, however as they were part of ongoing research they were not released until July 30, when the paper was published in the journal Science.
According to the ESA's Rosetta blog:
The images taken shortly before touchdown progressively reveal a surface comprising metre-size blocks of diverse shapes and random orientations, coarse regolith with grain sizes of 10–50 cm and, in the closest image, granules less than 10 cm across. The regolith in this region is thought to extend to a depth of 2 m in places, but seems to be free from fine-grained dust deposits at the resolution of the images.
The largest boulder, seen only in the images taken from distances between 67.4 m and 28.9 m, measures about 5 m high, with a peculiar bumpy structure and fracture lines running through it that suggest erosional forces are working to fragment the comet’s boulders into smaller pieces. The boulder also has a tapered ‘tail’ of debris behind it, yielding clues as to how particles lifted up from one part of the eroding comet are deposited elsewhere.
Although contact with the Philae lander has been intermittent, at best, the Rosetta spacecraft has been returning incredible results from its orbit around the comet, and the mission team here on Earth is preparing for Comet 67P's closest approach to the Sun (perihelion), which takes place on August 13. This most active period for the comet should reveal even more about the comet's structure and provide scientists with plenty more to study in the months and even years to come.