The past month has been an exciting time for the James Webb Space Telescope! After launching on Christmas Day, the telescope spent the next few weeks deploying its mirrors, checking the individual segments, and then maneuvering to L2, where it will spend the next ten to twenty years unlocking the mysteries of the cosmos. According to NASA Administrator Bill Nelson, the Chief Science Communications Officer (CSCO) for the JWST and the Hubble Space Telescope (HST) for the ESA, James Webb will begin collecting light this summer.
To mark the occasion, the Virtual Telescope Project (VTP) captured images of James Webb to give people a sense of what it looks like in orbit. Unfortunately, there’s not a lot to see there, other than a bright dot in the night sky. But like Carl Sagan’s famous “Pale Blue Dot” picture of Earth (taken by Voyager 1 on its way out of the Solar System), or Cassini’s “The Day Earth Smiled” image, there’s a tremendous amount of significance in that small point of light.
Newly discovered asteroid 2016 VA snuck up on us last night, and crossed through the Earth’s shadow to boot.
Discovered just yesterday by the Mount Lemmon Sky Survey based outside of Tucson Arizona, 2016 VA passed just 58,600 miles (93,700 kilometers) from the surface of the Earth this morning at 00:42 Universal Time (UT). That’s a little over 20% of the distance from the Earth to the Moon, and just over twice the distance to the ring of geosynchronous and geostationary satellites around the Earth.
This sort of close pass of a newly discovered asteroid happens a few times a year. What made 2016 VA’s passage unusual, however, was its transit through the Earth’s shadow. The discovery was announced yesterday by the Minor Planet Center, and astronomer Gianluca Masi soon realized that the Virtual Telescope Project had a unique opportunity to capture the asteroid on closest approach.
Gianluca Masi explained how the difficult capture was done:
“The image is a 60-second exposure, remotely taken with “Elena” (a PlaneWave 17” +Paramount ME+SBIG STL-6303E robotic unit) available at the Virtual Telescope project. The robotic mount tracked the extremely fast apparent motion of the asteroid, so stars are trailing. The asteroid is perfectly tracked; it is the sharp dot in the center, marked with two white segments. At imaging time, asteroid 2016 VA was at about 200,000 kilometers from us and approaching.”
Catching a fast-moving asteroid such as 2016 VA on closest approach isn’t easy. First off, there’s an amount of uncertainty surrounding the orbit of a newly discovered object until more observations can be made. 2016 VA passed close enough to the Earth that our planet’s gravity substantially altered the tiny asteroid’s future orbit. Also, a house-sized Earth-crosser like 2016 VA is really truckin’ across the sky on closest approach: 2016 VA was moving at 1500” a minute through Earth’s shadow – that’s 25” a second, fast enough to cross the apparent diameter of a Full Moon in just 72 seconds.
Masi also notes:
“During its flyby, asteroid 2016 VA was also eclipsed by the Earth. We covered the spectacular event, clearly capturing the penumbral effects. The movie is an amazing document showing the eclipse. Each frame comes from a 5-second integration.”
At an estimated 16 to 19 meters in size, 2016 VA shined at 13th magnitude as it crossed the southern hemisphere constellation of Sculptor on closest approach. It crossed through the Earth’s shadow for 11 minutes from 23:23 to 23:34 UT last night, just over an hour before closest approach. You can see the dimming effect of the Earth’s outer penumbral shadow in the video, just before the asteroid strikes the inner dark umbra and emerges back into eternal sunshine once again. Sitting on 2016 VA, and observer would have seen a total solar eclipse, as the bulk of the Earth passed between the asteroid and the Sun in an event not witnessed by the tiny world for thousands of years.
Such transits of asteroid through the Earth’s shadow have been observed before: 2012 XE54 crossed through the Earth’s shadow a few years back, and 2008 TC3 crossed through the Earth’s shadow before striking the Nubian desert in the early morning hours of October 7th, 2008.
2016 VA is also a similar size to another famous space rock: the 20 metre asteroid that exploded over the city of Chelyabinsk the day after Valentine’s Day in 2013. 2016 VA gave us a miss, and won’t make another pass as close to the Earth again for this century.
To our knowledge, such a video capture of an asteroid crossing through Earth’s shadow is a first, or at least the first that we’ve seen circulated on ye ole Web.
Congrats to the good folks at the Virtual Telescope Project for swinging into action so quickly, and providing us with an amazing view!
As NASA prepares to send a spacecraft to a distant asteroid, another space rock made a surprise visit to Earth’s vicinity. The newly discovered small asteroid, named 2016 RB1, passed safely by Earth, coming within approximately 23,900 miles (38,463 km) of our planet, or just outside the orbit of many communications satellites.
The asteroid passed by Earth at 1:28 p.m. Eastern Time (1728 UT).
Click on the image if it is not animating in your browser.
The asteroid was discovered on Monday, September 5 by the Mt. Lemmon Survey telescope in Tucson, Arizona. 2016 RB1 is estimated to be between 24 to 52 feet (7.3 – 16 meters) across, which is just a bit smaller than the Chelyabinsk meteor that exploded over northern Russian in February 2013, which was estimated to be around 56 ft (17 meters) wide.
On Thursday, September 8, NASA hopes to launch its OSIRIS-ReX mission to study asteroid Bennu and conduct a sample return, with the sample coming back to Earth by 2023. With the mission, scientists hope to learn more about the formation and evolution asteroids and of the Solar System as a whole.
Here’s a graphic comparing the small asteroid 2016 RB1 to other objects, compiled by Mikko Tuomela and Massimo Orgiazzi.
2016 RB1 is the third asteroid so far in September 2016 that traveled between the Earth and the Moon. Asteroid 2016 RR1 passed by at 0.32 lunar distances on September 2, and just a few hours later, asteroid 2016 RS1 passed by at 0.48 times the Earth-moon distance. But this latest asteroid pass is the closest, at 0.10 lunar distances.
From its orbit, astronomers have determined 2016 RB1 is likely an Aten asteroid, a group of Near-Earth Objects that cross the orbits of Earth, Venus and even Mercury.
This will be the 6th year that the Virtual Telescope Project has on an online Messier Marathon, and they’ll be using their robotic telescopes, providing real time images — all while chatting and sharing the passion and excitement with people from around the world.
Supernovae are some of the fascinating objects in the Universe. The Virtual Telescope Project will be hosting a live webcast today UPDATE: the webcast will also be on May 17, 2013 as clouds arrived shortly into the webcast on on the 16th) at 21:00 UTC (5 pm EDT, 2 pm PDT) to explore in real-time — from the comfort of your home or office –the exciting world of supernovae, those incredible, violent exploding stars. All this with the live commentary from a professional astrophysicist, Gianluca Masi.
During “The Exploding Universe: the Realm of Supernovae”, you can join in and surf the Cosmos in space and time, observing dying stars placed millions of light years way and shining as billions of Sun, while living the very final stages of their lives, before becoming a neutron star or a black hole.
Have you ever done a Messier Marathon? Want to try it online from the comfort of your own home? Astrophysicist Gianluca Masi will host a webcast today (April 9, 2013) at 18:00 UTC (2 pm EDT) (update: this webcast has been postponed due to clouds. We’ll post the new date and time when it becomes available). You can join in at this link, and explore the many treasures of the famous Messier Catalog. Masi said they will try to see as many of 110 objects in the Messier Catalog as possible in a single viewing session. This is what is called a Messier Marathon!
This is the fifth time the Virutal Telescope Project has attempted this, and they’ve had great success previously. Masi is doing the Marathon their robotic telescopes, and will provide real time images and live comments, along with answering your questions and “sharing your passion and excitement with friends from all around the world.”