We know that hundreds of thousands of asteroids orbit the Sun, and a very few have a high risk of striking Earth. There are also asteroids that haven’t been discovered yet that can surprise us, as evidenced by the explosion over Chelyabinsk, Russia, last February. This event was confirmation that an asteroid strike is a risk we do face. But also, how do scientists counter the pseudo-scientific claims and fears that asteroids seem to generate? And what opportunities do asteroids provide for mining useful resources?
Watch live today (Friday, October 25, 2013) at 15:00 UTC (11 am EDT) as astrophysicist Neil deGrasse Tyson, astronauts Rusty Schweickart, Tom Jones, Ed Lu, Soichi Noguchi and others discuss the research and the steps that are being taken to avoid these potential natural disasters. With current space technology, scientists know how to deflect the majority of hazardous near-Earth objects, but these technologies have not yet been tested in space, and prevention is only possible if nations work together on detection and deflection.
Here’s the latest attempt to hunt down the water leak that aborted Luca Parmitano’s spacewalk in July: two astronauts aboard the International Space Station removed and replaced a fan pump and water separator inside the spacesuit earlier this week.
All spacewalks with NASA suits are on hold while the agency investigates the leak, and they have been trying mightily. In late July, then on-station NASA astronaut Chris Cassidy demonstrated how the pool of water spread within the helmet (as you can see in these YouTube videos).
This week, on-orbit NASA astronauts Mike Hopkins and Karen Nyberg delved further. While the astronauts are trained before their missions on some suit repairs, this particular type was not something that was covered before they left Earth. After Mission Control walked them through what to do, the astronauts proceeded cautiously as they did the work, NASA said.
“Our engineering teams have identified several different components of the suit, designing a big fault tree, and this is just one of the components that we think could have contributed to the leak in the suit,” said Alex Kanelakos, an extra-vehicular activity flight controller and astronaut instructor, in a new YouTube video.
“Specifically, the water separator is what we’re concentrating our efforts on today.”
As Kanelakos explained, a motor inside the suit drives the fan pump and water separator. The fan circulates oxygen, and the pump pumps the coolant fluid. The water separator, meanwhile, takes out moisture (water) from the ventilation loop and gas that could be trapped inside the water coolant loop. The dried-out air is then returned to the crew member for breathing, and the cycle continues.
In September, Cassidy told Universe Today that the spacesuit is expected to come back to Earth during a future SpaceX Dragon cargo flight. That type of spacecraft is (unusually among space trucks) designed to survive re-entry in the atmosphere, allowing engineers on the ground to examine the spacesuit after it comes back.
Cassidy added that the situation was serious, and he supported NASA’s decision to end the spacewalk (which he was also participating in.) He didn’t think, however, that Parmitano was in immediate danger of drowning. For his part, Parmitano wrote a blog post on the European Space Agency website after his spacewalk, saying that space is an “inhospitable” arena.
As any astronaut is trained to do, Parmitano did consider other contingencies while the leak was happening, he wrote:
“The only idea I can think of is to open the safety valve by my left ear: if I create controlled depressurisation, I should manage to let out some of the water, at least until it freezes through sublimation, which would stop the flow. But making a ‘hole’ in my spacesuit really would be a last resort,” he wrote.
That fix, however, was not implemented as Parmitano and Cassidy made their way back to the station in time for their crewmates to repressurize the hatch and bring their Italian crewmate safely inside.
Undoubtedly, you’ve been seeing the recent images of Comet ISON now that it is approaching its close encounter with the Sun on November 28. ISON is currently visible to space telescopes like the Hubble and amateur astronomers with larger telescopes. But you might be wondering why many images show the comet with a green-ish “teal” or blue-green color.
Amateur Astronomer Chris Schur has put together this great graphic which provides information on the spectra of what elements are present in the comet’s coma.
For the conspiracy theorists out there, the green color is actually a good omen, and lots of comets display this color. The green color is a sign the comet is getting more active as gets closer to the Sun – meaning it is now putting on a good show for astronomers, and if it can continue to hold itself together, it might become one of the brightest comets in the past several years.
“ISON’s green color comes from the gases surrounding its icy nucleus,” says SpaceWeather.com’s Tony Phillips. “Jets spewing from the comet’s core probably contain cyanogen (CN: a poisonous gas found in many comets) and diatomic carbon (C2). Both substances glow green when illuminated by sunlight in the near-vacuum of space.”
Both are normally colorless gases that fluoresce a green color when excited by energetic ultraviolet light in sunlight.
And if those poisonous gasses sound dangerous, don’t worry. They are spread out in space much too thinly to touch us here on Earth. So don’t fall prey to fear mongers who are out to bilk the masses – like people did in 1910 when Comet Halley made a return to the skies and swindlers pitched their ‘gas masks’ and special ‘comet pills’ for protection. And of course, nothing happened.
But back to the color. Chris Schur provided this info along with his graphic:
Your readers may appreciate knowing why comets can appear this color. The background image is the shot I took with my 12.5″ and an ST10xme CCD camera for 20 minutes in mid-October. A pale coloration of the front of the coma is seen. To the lower left is a shot with the same instrument but with a 100 lpmm (line pair per millimeter) diffraction grating in front of the CCD chip to break out the spectra of the objects in the entire field.
Here ISON is faintly seen to the left of center, and the first order spectra a band to its right. But the real answer comes when we use the software called Rspec to analyze this band of light. The result is on the lower right. Normally reflected sunlight is rather flat and bland, and mostly that is what ISON is right now, reflected from dust. But labeled are two humps in the blue and green parts of the spectrum labeled “C2” for a carbon molecule. This blue/green emission pair is what gives ISON the color.
Chris notes that as the comet nears the Sun, astronomers and astrophotographers will be able to resolve more spectral details in the comet. “It will be exciting to watch the changes as more molecules pop out,” Chris said via email, “and possibly when it is closest to the Sun, we just may see some metal lines like iron or magnesium from MELTED vaporized rock. How exciting!”
And for those who insist there is something nefarious about Comet ISON, take a look at this FAQ from our friend Stuart Atkinson, who hosts the great site Waiting for ISON. He addresses the many conspiracy theories that are out there regarding this comet.
How’s that for a beacon? NASA’s Chandra X-ray Observatory has tracked down evidence of at least a couple of past luminous outbursts near the Milky Way’s huge black hole. These flare-ups took place sometime in the past few hundred years, which is very recently in astronomical terms.
“The echoes from Sagittarius A were likely produced when large clumps of material, possibly from a disrupted star or planet, fell into the black hole,” the Chandra website stated.
“Some of the X-rays produced by these episodes then bounced off gas clouds about 30 to 100 light years away from the black hole, similar to how the sound from a person’s voice can bounce off canyon walls. Just as echoes of sound reverberate long after the original noise was created, so too do light echoes in space replay the original event.”
The astronomers saw evidence of “rapid variations” in how X-rays are emitted from gas clouds circling the hole, revealing clues that the area likely got a million times brighter at times.
Watch out, asteroid 1999 JU3: you’re being targeted. As severalmediareports reminded us, the Japan Aerospace Exploration Agency (JAXA)’s Hayabusa-2 asteroid exploration mission will carry a ‘space cannon’ on board — media-speak for the “collision device” that will create an artificial crater on the asteroid’s surface.
“An artificial crater that can be created by the device is expected to be a small one with a few meters in diameter, but still, by acquiring samples from the surface that is exposed by a collision, we can get fresh samples that are less weathered by the space environment or heat,” JAXA states on its website.
Reports indicate JAXA is on schedule to, er, shoot this thing into space for a 2018 rendezvous with an asteroid. The spacecraft will stick around the asteroid for about a year before heading back to Earth in 2020. The overall aim is to learn more about the origin of the solar system by looking at a C-type asteroid, considered to be a “primordial body” that gives us clues as to the early solar system’s makeup.
This beautiful new view of Comet ISON comes from a collaborative effort between astrophotographers Cliff Spohn in Ohio and Terry Hancock in Michigan, taken on October 21, 2013. “The first time in almost two weeks that we have had a break in the clouds and rain we could not miss this rare opportunity to capture ISON using Cliff’s equipment,” said Terry via email. “Credit goes to Cliff for capturing the object while I did the calibration, stacking in CCDStack post processing in CS5 and video editing.”
You can see a timelapse video below, covering 93 minutes of imaging, again on October 21. It’s obvious ISON is still intact and it continues to bright, as it is currently about magnitude 9.
More recent images:
Update: This new one is just in from astrophotographer Damian Peach, and its a beauty! Taken on October 24.
From John Chumack: “I just had to try just a telephoto on Comet ISON while it was near Mars,” John said via email. This view shows Comet ISON (C/2012 S1) near Mars and Regulus, the brightest star in the constellation Leo. This image was taken on October 18, 2013 from
Warrenton, Virginia at 6:27am EST looking over Washington D.C.
This nice image comes from Chris Schur from Arizona, taken on October 14, and is also of the conjunction. “As you may recall, on this date of 10/14 the three objects were in a perfect line going from south to north in Leo,” Chris said via email. “What a spectacular sight in the 11 x 80 binoculars! While the comet was quite faint, a short 1/4 degree of tail could be seen, and the gorgeous blue and orange colors of the planets.”
Chris used a Canon Xti, ASA800 with 10 minutes total integration time, with a 80mm f/4.8 Ziess APO refractor on a Televue GEM. Taken from Payson, Arizona at 5,100 feet elevation.
Here’s your amazing oh-my-gosh-space-is-so-cool video of the day — a “canyon of fire” forming on the Sun after the liftoff and detachment of an enormous filament on September 29-30. A new video, created from images captured by the Solar Dynamics Observatory (SDO) and assembled by NASA’s Goddard Space Flight Center, shows the entire dramatic event unfolding in all its mesmerizing magnetic glory.
Watch it below:
Solarrific! (And I highly suggest full-screening it in HD.) That filament was 200,000 miles long, and the rift that formed afterwards was well over a dozen Earths wide!
Captured in various wavelengths of light by SDO’s Atmospheric Imaging Assembly (AIA) the video shows the solar schism in different layers of the Sun’s corona, which varies greatly in temperature at different altitudes.
According to the description from Karen Fox at GSFC:
“The red images shown in the movie help highlight plasma at temperatures of 90,000° F and are good for observing filaments as they form and erupt. The yellow images, showing temperatures at 1,000,000° F, are useful for observing material coursing along the sun’s magnetic field lines, seen in the movie as an arcade of loops across the area of the eruption. The browner images at the beginning of the movie show material at temperatures of 1,800,000° F, and it is here where the canyon of fire imagery is most obvious.”
Now, there’s not really any “fire” on the Sun — that’s just an illustrative term. What we’re actually seeing here is plasma contained by powerful magnetic fields that constantly twist and churn across the Sun’s surface and well up from its interior. The Sun is boiling with magnetic fields, and when particularly large ones erupt from deep below its surface we get the features we see as sunspots, filaments, and prominences.
When those fields break, the plasma they contained gets blasted out into space as coronal mass ejections… and this is what typically happens when one hits Earth. (But it could be much worse.)
Astronauts have said adapting to weightlessness is much easier than readapting to gravity when they returned to Earth. Muscle weakness, wobbly legs, and feeling like the room is spinning is common after long duration spaceflight, not to mention the long-term issues like bone loss, diminished eyesight, and a heart that has to recondition itself to pump blood harder to overcome gravity. As Canadian Chris Hadfield said, “My body was quite happy in space without gravity.”
It turns out spiders have similar issues. This Phiddipus Johnsoni, or red-backed jumping spider named Nefertiti is shown walking and preying on flies in her habitat while in orbit on the International Space Station and then doing the same while readapting to gravity on Earth. While trying to capture its prey, it ends up flopping awkwardly onto its back. No more flying like SuperSpider.
Nefertiti was in space 100 days in 2012 as part of a student-initiated science experiment of YouTube’s Space Lab, an online video contest. After returning home, this spidernaut was sent to the Smithsonian Institution’s National Museum of Natural History in Washington, D.C. and was part of exhibition of the first jumping spider to survive the trip to space. Unfortunately Nefertiti died just a few days after being sent to the museum.
Cargo resupply ships are vital for space exploration. These days they bring food, experiments and equipment to astronauts on the International Space Station. And in recent years, it hasn’t just been government agencies sending these things up; SpaceX’s Dragon spacecraft and (just this week) Orbital Sciences’ Cygnus spacecraft brought up cargo of their own to station in recent months.
NASA just published a brief timeline of (real-life) cargo spacecraft, so we thought we’d adapt that information in pictorial form. Here are some of the prominent members of that elite group. Did we miss anything? Let us know in the comments.
The space age began on October 4, 1957 with the launch of the first artificial satellite, Sputnik 1. This tiny spacecraft lasted only three months in orbit, finally burning up in the Earth’s atmosphere.
Following in these historic footsteps, many more spacecraft have been sent into Earth’s orbit, around the Moon, the Sun, the other planets, and even out of the Solar System itself. At the time that I’m recording this video, there are 1071 operational satellites in orbit around the Earth. 50 percent of which were launched by the United States.
Half of that 1071 are in Low-Earth Orbit, just a few hundred kilometers above the surface. Some of the most notable of these include the International Space Station, the Hubble Space Telescope, and many Earth observation satellites.
About a twentieth are in Medium-Earth Orbit, around 20,000 kilometers up, which are generally global positioning satellites used for navigation. A small handful are in elliptical orbits, where their orbit brings them closer and further to the Earth.
The rest are in geostationary orbit, at an altitude of almost 36,000 kilometers.
If we could see these satellites from Earth’s surface, they would appear to hang motionless in the sky. The fact that they remain over the geographic same area means they provide the perfect platform for telecommunications, broadcast or weather observations.
But there are many, many more artificial objects orbiting the Earth. In this collection of space debris we’re talking spent boosters, dead satellites, and even misplaced gloves. According to the United States Space Surveillance Network, there are more than 21,000 objects larger than 10 cm orbiting the Earth. Just a small fraction of these are operational satellites. It’s estimated there are a further 500,000 bits and pieces between 1 and 10 cm in size.
Near Earth orbit is so polluted with junk that the International Space Station is often moved to avoid impact with dangerous chunks of space debris. Many of these objects are created through collisions, and some scientists are worried that future space travel might be too risky if we get too much junk orbiting the planet. We might seal ourselves inside a shield of shrieking metal moving at 29,000 km/hour.
Looking outwards from our own orbit, at any time there are a handful of satellites orbiting the Moon. Right now, NASA’s Lunar Reconnaissance Orbiter and Lunar Atmosphere and Dust Environment Explorer are in lunar orbit. Further still, there’s 1 spacecraft around Mercury, 1 at Venus, 3 visiting Mars and 1 orbiting Saturn. There’s a handful of spacecraft orbiting the Sun, although they’re leading or trailing the Earth in its orbit. And a few spacecraft are on trajectories to take them out of the Solar System entirely. NASA’s Voyager spacecraft, exited the Sun’s heliosphere in 2013, and entered the interstellar medium.
Starting with Sputnik’s lonely journey over 50 years ago, It’s amazing to consider just how many satellites we’ve already launched into space in just a few decades. With more launches all the time, space is becoming a busy place, with so many exciting missions to look forward to.
We have written many articles about satellites for Universe Today. Here’s an article about two satellites that collided in Earth orbit, and here are some pictures of satellites.