Universe Today

September 26, 2012December 23, 2015 by Nancy Atkinson

Space Debris Threat May Require Avoidance Maneuver for Space Station

The International Space Station. Credit: NASA

UPDATE (9/27/2012, 13:00 UTC) NASA now says that with additional tracking, they have determined the two pieces of space debris do not pose a threat to the ISS, and a debris avoidance maneuver scheduled for Thursday morning was cancelled by the flight control team at Mission Control. The ATV undocking time on Friday is still being decided at the time of this posting. See additional info at NASA’s website. (End of update)

International Space Station officials are keeping a watchful eye on two different pieces of space junk that may require the ISS to steer away from potential impact threats. Debris from the Russian COSMOS satellite and a fragment of a rocket from India may come close enough to the space station to require a debris avoidance maneuver. If needed, the maneuver would be done using the ESA’s Automated Transfer Vehicle (ATV) “Edoardo Amadi.” The ATV was supposed to undock last night, but a communications glitch forced engineers to call off the departure.

Both pieces of debris are edging just inside the so-called “red zone” of miss distance to the station with a time of closest approach calculated to occur Thursday at 14:42 UTC (10:42 a.m. Eastern time.) It is not known how large the object is.

An approach of debris is considered close only when it enters an imaginary “pizza box” shaped region around the station, measuring 1.5 x 50 x 50 kilometers (about a mile deep by 30 miles across by 30 miles long) with the vehicle in the center.

NASA says the three-person Expedition 33 crew is in no danger and continues its work on scientific research and routine maintenance. The current crew includes NASA astronaut Sunita Williams, Japanese astronaut Akihiko Hoshide and Russian cosmonaut Yuri Malenchenko.

If the maneuver is required – and NASA said it could be called off any time — it would occur at 12:12 UTC (8:12 a.m. EDT) Thursday, using the engines on the ATV, which remains docked to the aft port of the Zvezda Service Module. It usually takes about 30 hours to plan for and verify the need for an avoidance maneuver.

Debris avoidance maneuvers are conducted when the probability of collision is greater than 1 in 100,000, if it will not result in significant impact to mission objectives. If it is greater than 1 in 10,000, a maneuver will be conducted unless it will result in additional risk to the crew.

Only three times during the nearly 12 years of continual human presence on the ISS has a collision threat been so great that the crew has taken shelter in the Soyuz vehicles. (Those events occured on March 12, 2009, June 28, 2011 and March 24, 2012.) During those events, the station was not impacted. While the ISS likely receives small micrometeoroid hits frequently (based on experiments left outside the ISS and visual inspections of the station’s hull) no large debris impacts have occurred that have caused depressurization or other problems on the ISS.

Tuesday’s initial attempt to undock the ATV was called off due to a communications error between the Zvezda module’s proximity communications equipment and computers on the ATV. Russian engineers told mission managers that they fully understand the nature of the error and are prepared to proceed to a second undocking attempt, which has been postponed to Friday at the earliest, due to the potential space debris threat.

Once it is undocked, the ATV will move to a safe distance away from the station for a pair of engine firings that will send the cargo ship back into the Earth’s atmosphere to burn up over the Pacific Ocean.

The ATV still has extra fuel on board, and so the decision was made that if need, that available resource would be used.

Here’s the info on NASA’s criteria for performing debris avoidance maneuvers.

Source: NASA

*this article has been updated

September 26, 2012December 23, 2015 by Nancy Atkinson

The Dust “Windshield Wiper” That Didn’t Go to Mars

A device that works as a windshield wiper to eliminate Mars dust from the sensors on Mars spacecraft. Credit: UC3M

In the past when we’ve discussed how dust accumulates on the solar panels of the Mars Exploration Rovers, Spirit and Opportunity, the most-often posted comments on those articles usually said something like, “They should have developed a windshield-wiper-like device to get rid of the dust!” Our readers will be happy to know such a device has now been invented. A team of researchers created extremely lightweight wipers that could be used to remove dust on Mars spacecraft. In fact, the researchers from Universidad Carlos III in Madrid, Spain developed the device for the Curiosity rover, but unfortunately, it wasn’t used for the MSL mission. But it’s ready to go for future Mars landers and rovers

While Curiosity doesn’t have solar panels, (it instead uses a longer-lasting RTG for power – a Thermoelectric Generator, which is a power system that produce electricity from the natural decay of plutonium-238) it does have sensors that can be affected by the accumulation of dust, such as the meteorological station, the Rover Environmental Monitoring Station (REMS).

The UC3M team created a brush made up of Teflon fibers, designed to clean the ultraviolet sensors on REMS.

“In our laboratories, we demonstrated that it worked correctly in the extreme conditions that it would have to endure on Mars,” said Luis Enrique Moreno, a professor who was head of the project, “with temperatures ranging between zero degrees and eighty below zero Celsius, and an atmospheric pressure one hundred times lower than that of the earth.”

Because weight is an issue when launching objects to other worlds, they used a very lightweight material for the wiper actuators, made from shape memory alloys (SMA), a very light nickel and titanium alloy that allows movement when the composite is heated.

“The main advantage is that these alloys produce a material that is very strong as related to its weight, that is, a thread of less than one millimeter can lift a weight of 4 or 5 kilograms,” said Moreno. “The problem presented by these mechanisms is that, because they are based on thermal effects, they are not as efficient as motor technology, although they are much lighter, which is a very important consideration in space missions.”

This group and other research groups at UC3M are currently working on a second, more elaborate prototype based on SMA technology. It will be used to clean dust from fixed meteorological stations that would be part of the MEIGA-METNET mission, a proposed Mars lander developed by Finnish Meteorological Institute, along with groups from Russia and Spain to do atmospheric observations, but which is not yet part of an official mission yet.

Here’s a look at the proposed unique landing proposed for METNET:

“We are also using this technology to develop the exoskeletons used to aid people with mobility problems, trying to substitute motors with these materials, in order to reduce the devices’ weight and increase agility in their use,” said Moreno, adding that this new product could even be used in the future to improve the joints on the gloves used by astronauts during EVAs.

Source: Universidad Carlos III

September 26, 2012December 23, 2015 by Jason Major

Take a Gander at a Cosmic Gull

The head and “eye” of the Seagull Nebula (ESO)

This colorful new image from ESO’s La Silla Observatory highlights the heart of a shining stellar nursery located between the constellations Monoceros and Canis Major. Officially named Sharpless 2-292, the cloud of gas and dust forms the “head” of the Seagull Nebula (IC 2177) and gets its glow from the energy emitted by the young, bright star within its “eye”.

A wide-angle image of the Seagull Nebula shows the soaring birdlike shape that gives it its nickname. The cloud seen above forms the gull’s head.

A wide-field view of the Seagull Nebula from the ESO’s Digitized Sky Survey 2 (ESO/Digitized Sky Survey 2. Acknowledgement: Davide De Martin)

The wings of this gull span an impressive 100 light-years from tip to tip. A birthplace for new stars, the nebula is located within our galaxy about 3,700 light-years away.

For an idea of how far that is, if the distance between the Sun and Earth were scaled down to 1 inch (2.5 cm) and you were standing in New York City, the stars in the Seagull Nebula would be in Paris, France (considering the most direct flight route.)

Powerful radiation from young stars causes the surrounding hydrogen gas to glow with a red color. Light from the hot blue-white stars also gets scattered off tiny dust particles in the nebula to create a blue haze.

A Crescent Moon in the Martian Sky

Raw image of Phobos above Mars, taken by Curiosity's Mastcam in September 2012. Credit: NASA/JPL-Caltech

Mars’ moon Phobos is captured in a daytime image by Curiosity (NASA/JPL-Caltech/MSSS)

A raw image taken on September 21 by Curiosity’s right Mastcam shows a daytime view of the Martian sky with a crescent-lit Phobos in the frame… barely visible, yes, but most certainly there. Very cool!

The image above is a crop of the original, contrast-enhanced and sharpened to bring out as much detail as possible.

The 13-km-wide Phobos has been spotted several times before by Mars rovers, most recently during a solar transit on September 13 (sol 37) but I’m not sure if it’s ever been clearly captured on camera during the day before (i.e., not passing in front of the Sun.) If not, this will be a first!

See the latest news from the Curiosity mission here.

Added 9/28: According to Universe Today publisher Fraser Cain, this is “the most dramatic space picture of the year”… whether you agree or not, hear what he had to say on this and other recent news during the September 27 episode of the Weekly Space Hangout.

September 25, 2012December 23, 2015 by Nancy Atkinson

Red Bull Stratos Targets Oct. 8 for Record-Setting Freefall Attempt

Felix Baumgarter (center) and the Red Bull Stratos team are ready to attempt a record-setting freefall from the stratosphere. Credit: Red Bull

The countdown is on for Felix Baumgartner’s jump from the stratosphere. Red Bull Stratos reports that the space capsule Baumgartner will used has passed high-altitude simulation testing after it was damaged in July’s final practice jump, and a launch date has been set for October 8 in Roswell, New Mexico.

Baumgartner will leap from the edge of space, attempting to not only break the sound barrier with his body, but also break the record for the longest freefall.

As no one has successfully jumped from this height before, it’s uncertain what the highest supersonic freefall in history will look or feel like. The animated video below, provides a sense of what to expect during the attempt.

“After years of training with my team of dedicated Red Bull Stratos experts, I’ll be going on a journey that no one has ever done,” Baumgartner told Universe Today in 2010 in an email message. “If I succeed, I will be the first person to break the sound barrier, alone. That will be a record for all eternity. As such, a piece of me will become immortal. That excites me.”

43-year-old Baumgartner is hoping to jump from nearly 37 km (23 miles, 120,000 feet) to break the current jump record held by Joe Kittinger a retired Air Force officer, who jumped from 31,500 meters (31.5 km, 19.5 miles, 102,000 ft) in 1960. Now 83, Kittinger is assisting Baumgartner in preparations for the jump.

Baumgartner said he is delighted that “go” has been given for the attempt.

“I feel like a tiger in a cage waiting to get out,” said Baumgartner, a B.A.S.E. jumpers and extreme athletes, who in 2003 became the first person to make a freefall flight across the English Channel with the aid of a carbon wing. He will be flying as fast as speeding bullet during his supersonic journey to Earth.

The Red Bull Stratos team is trying to involve the public as much as possible. They will webcast the freefall attempt, and there’s even a contest to estimate where Baumgartner will land.

Baumgartner and the Red Bull Stratos team have been preparing for years to break the record for highest-altitude jump. The capsule, which at about 1.315 kilograms (2,899 pounds) weighs a little bit more than a VW Beetle, was damaged in a hard landing following Baumgartner’s final test jump from a near-record altitude of 29,610 meters (97,146 feet) in July – during the jump Baumgartner was freefalling at speeds of up to 536 mph / 864 kilometers per hour, or as fast as a commercial airliner. The Austrian landed safely in another part of the New Mexico desert.

Red Bull Stratos says the central aim of the project is to collect valuable data for science that could ultimately help improve the safety of space travel and enable high-altitude escapes from spacecraft. The jump will also attempt to break an assortment of records such as highest speed in freefall, highest jump, highest manned balloon flight and longest freefall.

They are cautiously optimistic about the launch date of October 8, while acknowledging that perfect weather conditions are needed for the delicate 30 million cubic feet / 850.000 cubic meters helium balloon, which is made of plastic that has 1/10th the thickness of a Ziploc bag. Mission meteorologist Don Day confirmed, “Early fall in New Mexico is one of the best times of the year to launch stratospheric balloons.”

September 25, 2012December 23, 2015 by Fraser Cain

Gape Slack-Jawed at this Amazing Video of Jupiter’s Rotation

Mike Phillips was already an accomplished planetary astrophotographer, but he took everything to the next level with this amazing video of Jupiter. In order to create these 8 seconds of awesomeness, Mike filmed Jupiter for a consecutive 1.5 hours on September 12, 2012. Then he batched up groups of frames and stacked them together to pull out even higher resolution. Then he stitched the whole thing back together to create a video that shows off Jupiter’s rotation.

Just stacking up video to create a single image is difficult work, but doing this kind of animation really takes things to the next level. And Mike’s just getting started. Once Jupiter reaches opposition, he thinks he’ll be able to get a full rotation of the giant planet.

You might want to check out Mike’s post on Google+, where he responds to other astrophotographers explaining his technique. Mike has also promised a tutorial… that would be nice.

One of the commentartors, Thad Szabo, noted:

I didn’t realize you had constructed your own version of Voyager and gotten launch capability…

Wait… you shot this from Earth’s surface???

Exactly.

Mike shot the video of Jupiter through his home made f/4.5 14″ Newtonian telescope

September 25, 2012December 23, 2015 by Andy Tomaswick

Study Looks at Making Asteroid Mining Viable

Artist concept of the Robotic Asteroid Prospector. Credit: Marc Cohen et al.

There’s been a lot of buzz in the media lately about mining asteroids, largely brought on by the introduction of Planetary Resources, Peter Diamandis’ new venture into the industry. But is this business proposition actually viable? NASA’s Innovative Advanced Concepts is funding a study that hopes to answer that question.

Called the Robotic Asteroid Prospector proposal, the project is part of the NIAC’s Phase I program awardees. It is headed by Dr. Marc Cohen, an architect based in Palo Alto California, with help from Warren James, a trajectory expert, Kris Zacny, a roboticist at Honeybee Robotics and Brad Blair, a mineral economist. Their proposal studies the fundamentals of some major questions facing the asteroid mining industry. What kinds of mission and spacecraft design are necessary? Is the right kind of mining technology available? And most importantly, is there even a viable business model for doing it in the first place?

Dr. Cohen himself is skeptical that there is, but points out that’s part of the reason he’s so interested in performing the research. Contributing to his skepticism are the numerous assumptions the proposal is based on. These include a telescope in Venus orbit to help the search for near-Earth objects (one of NASA’s primary mission statements, and similar to the B612 Foundation’s space telescope that will hunt for Near Earth Asteroids) and regular commercial access to a service base located in a Lagrange point from which to launch the missions.

“We’re trying to make the assumptions really clear, specific and explicit, so we understand what the trade-offs are,” Dr. Cohen told Universe Today. “One thing we’re being very careful about is not going in with any preconceptions.”

The assumptions lead to a spacecraft design, possibly using a solar-thermal propulsion system, that launches to a NEO from the Lagrange point station, mines and processes the material at the asteroid and then returns it to the Lagrange point for shipment back to Earth.

Dr. Cohen explained that the team is trying to find the requirements that would make a robotic asteroid program commercially successful.

There are still plenty of challenges to solve, including developing trajectories that allow the spacecraft to make repeated, short trips to the asteroid it is mining and handling any sort of technical problems without a human presence nearby. If it manages to resolve some of those difficulties, the project could result in the outlines of one of the backbones of the future space economy. It might also attract funding for the Phase II round of funding from NIAC next year.

For more information about the RAP, see the NIAC website

September 25, 2012December 23, 2015 by Nancy Atkinson

Guest Post: Comet Kerfuffle

An image generated from Starry Night software of how Comet ISON may look on November 22, 2013 from the UK.

Editor’s note: This guest post was written by Stuart Atkinson, a space and astronomy enthusiast who blogs at Cumbrian Sky, Road to Endeavour, which follows the Opportunity rover, and The Gale Gazette which discusses imagery from the Curiosity rover.

Unless you’ve been cut off from the internet today you’ll have heard about The Comet. No, not Comet PANSTARRS, which is due to shine in the sky next March, perhaps rivalling the fondly-remembered Comet Hale Bopp from 1996, but another comet. Comet 2012/S1, or “Comet ISON” to give it its full name. It’s everywhere you look on Twitter, Facebook, Google Plus. Why? Because initial calculations of its orbit show it will pass ridiculously close to the Sun next November, skimming the solar surface at a height of just under two million kilometres. And that means it might shine jaw-droppingly bright in the sky at that time, before it heads back off into deep space again.

So, of course, adding two and two to get fifty, there are lots of people getting more excited about this comet than a dog in a lamp post factory. If you were to believe some of the comments being written about it, it is absolutely nailed-on guaranteed to shine like a welding torch in the sky next November, blazing at magnitude -16, with a tail stretching across the sky like a WW2 searchbeam.

Can we all just calm down, please?

Although Comet ISON looks promising, very promising in fact, it’s very early days. It needs to be observed a lot more before we know exactly what’s in store for us, and even then what it will actually look like in the sky is impossible to predict this far ahead. You see, comets are notoriously unreliable, and love nothing better than getting astronomers on Earth all fired up with the promise of a dazzling nocturnal display before fizzling out and being so faint they need binoculars to see them. Hardly surprising, seeing as comets are essentially great big chunks of dirty ice, and we only see them because they’re melting and falling to pieces as they race around the Sun. You can’t predict how that will work out now, can you?

There’s a whole spectrum of possibilities here. At one end of that spectrum, ISON will live up to the most breathless predictions and blaze in the sky like a science fiction movie special effect. Its tail will span half the sky, becoming visible as soon as the Sun has set, and we will stand on our hillsides and in our gardens looking at it and slowly shaking our heads in wonder before we remember we’ve actually got a camera set up, and start taking pictures of it.

At the other end of the spectrum, ISON will play us all for fools, and even before its close solar flyby it will break up without developing a searchbeam tail, and we’ll all stand on our hillsides and in our gardens looking at it through binoculars and shaking our fists at it angrily, cursing its icy crust.

I think we should cross our fingers for something between the two. We should hope that ISON stays in one piece, survives its close encounter with the Sun, and shines in the twilight sky next November like another Lovejoy or McNaught. I’ll be happy with that, to be honest. Because I’m a citizen of the northern hemisphere my only views of Lovejoy were on my computer monitor, as I drooled over the images of it taken by astronomers and skywatchers in Australia and New Zealand and across the southern hemisphere. I caught a fleeting glimpse of McNaught from here in Kendal – standing in the ruins of the castle that stands above my town, I saw the comet through binoculars through a brief gap in the clouds, as I stood in the rain – but again I ‘saw’ it online rather than with my own eyes, cursing (good naturedly) all those people south of the equator who were seeing the real thing shining in their sky…

An image generated from Starry Night software of how Comet ISON may look on November 29, 2013 from the UK.

(I have to be honest here: having missed the last two Great Comets because of my latitude, when I fired up STARRY NIGHT earlier today, and stepped forward in time to next November, I experienced a rather ungentlemanly “Ha! Our turn!” moment of pure smugness as I saw that ISON’s path will carry it through my sky..!)

The best thing we can do, seriously, is just cross our fingers. Hope for the best, but prepare for…something less than that.

And yet…

Comets are magical, aren’t they? They bring out the dreamer, the optimist and the romantic in all of us. And although I’m fighting it, my head is full of images as I write this, memories of the comets I have seen before, and wondering what ISON will bring. I remember my first sighting of Halley’s Comet, on Guy Fawkes Night 1985. It was just a smudge of a blur in my binoculars, as I stood on the sports playing field near my home, breathing in the smell of bonfires and fireworks in the darkness; I remember standing in the deep, dark Cumbrian countryside, in the gravelled gateway of a farm field, and tracing out the ridiculous extent of Comet Hyakyutake’s pale green tail across the star-spattered sky; and I remember standing in the centre of the ancient Castlerigg stone circle outside Kewsick and, in perfect silence, and feeling a real connection to the watching Comet Hale-Bopp shining above the fells, its twin tails looking like they had been sprayed across the heavens by some cosmic grafitti artist…

What memories will I have after Comet ISON has flown past the Sun, I wonder…

It’s tempting to look at the elements of this comet, and to simulate its apparition using planetarium software, and to get excited. But really, let’s take it easy. I mean, we’ve been here before. Some comets in the past have promised the Earth (mentioning no names… *cough* Kohoutek *cough* ) only to pass by without any real fanfare or fuss, leaving astronomers with a lot of egg on their faces.

So, everyone, take a deep breath, and look at the calendar. ISON is going to be in the sky next November. NEXT November. That’s over a year away. Anything could happen before then.

And yet…

By Stuart Atkinson

September 25, 2012December 23, 2015 by Nancy Atkinson

Will NASA Really Build a “Gateway” L-2 Moon Base?

In this artist’s concept, the Orion MPCV is docked to a habitat; an astronaut exits the spacecraft to conduct an EVA. Credit: NASA

Over the weekend, The Orlando Sentinel reported that NASA is considering building a hovering outpost beyond the Moon at L-2 (Lagrangian point 2) that will be a ‘gateway’ to serve as a point for launching human missions to Mars and asteroids. The buzz among the space-related social medias ranged from “this is the greatest idea ever” to “this is make-work for the Space Launch System, (NASA’s new rocket.)” The newspaper’s report cited a White House briefing given in September by NASA Administrator Charlie Bolden, but said “it’s unclear whether it has the administration’s support. Of critical importance is the price tag, which would certainly run into the billions of dollars.”

As always, money is the real issue with any grand ideas that anyone at NASA may have.

And NASA has now officially responded to the The Sentinel’s report and said… well, actually they didn’t really say much at all. Here’s the NASA statement:

“NASA is executing President Obama’s ambitious space exploration plan that includes missions around the moon, to asteroids, and ultimately putting humans on Mars. There are many options – and many routes – being discussed on our way to the Red Planet. In addition to the moon and an asteroid, other options may be considered as we look for ways to buy down risk – and make it easier – to get to Mars. We have regular meetings with OMB (Office of Management and Budget), OSTP(Office of Science and Technology) , Congress, and other stakeholders to keep them apprised of our progress on our deep space exploration destinations. This concept is a part of the Voyages document that we mentioned in an earlier Update posted on NASA.gov in June: http://go.nasa.gov/NASAvoyages.” Refer to page 26 of the chapter titled, “Habitation and Destination Capabilities.”

And so NASA does not deny they are looking into building such a base, and in the document mentioned above, they do provide some interesting details about why exploring cis-lunar space would be important: for scientific reasons, for technological and economic growth and to pave the way for future exploration.

And so, what would a space station beyond the Moon be like? The Sentinel suggested it could be built in a budget-conscious way using parts left over from the International Space Station and be placed at what’s known as the Earth-Moon Lagrange Point 2, a spot about 38,000 miles beyond the far side of the Moon and 277,000 miles from Earth where the gravitational pull of Earth and the Moon are at equilibrium, so that a spacecraft could basically “hover” in a fixed spot.

In the document, NASA says the habitat they are designing combines technologies to accommodate a crew of at least four, potentially six for a mission to Mars. The in-space version of the habitat will require docking systems for crew transportation vehicles, and it could be used in cis-lunar space as a Lagrange point facility, or in transit to deep-space destinations, or near a NEA.

Artist’s concept of an inflatable cis-lunar facility, or Lagrange gateway. Credit: NASA

They call the L-2 Gateway base an “ISS Stepping Stone,” saying that the ISS is an invaluable resource for researching and testing exploration capabilities in space, and it may inspire future space station concepts.

“As NASA looks to explore beyond LEO, the agency is considering how a facility in cis-lunar space, potentially stationed at an Earth-Moon Lagrange point, could support research, testing, and astronomical observation, as well as provide a staging point for exploration missions. Such a facility, also known as a Lagrange gateway, would build upon ISS hardware and experience, and would serve as an initial in-space habitat, providing a basis for future long-duration habitation developments.”

Could this ‘Gateway’ idea really fly?

The Sentinel says that from NASA’s perspective, the outpost solves several problems.

“It gives purpose to the Orion space capsule and the Space Launch System rocket, which are being developed at a cost of about $3 billion annually. It involves NASA’s international partners, as blueprints for the outpost suggest using a Russian-built module and components from Italy. And the outpost would represent a baby step toward NASA’s ultimate goal: human footprints on Mars.” — Orlando Sentinel

The report doesn’t mention budget or costs, and if the federal government cuts budgets in the name of deficit reduction, it is very unlikely that NASA will get more money — and it likely could get less – than the current budget of $17.7 billion.

If the past is any indication of the future, this report may wind up like Werner von Braun’s 1950’s vision of getting humans to Mars: a report that future generations look back on and say, “wish we could have done that, and why can’t we do that now?”

September 25, 2012December 23, 2015 by Jason Major

How Many Asteroids Are Out There?

Answer: a LOT. And there’s new ones being discovered all the time, as this fascinating animation by Scott Manley shows.

Created using data from the IAU’s Minor Planet Center and Lowell Observatory, Scott’s animation shows the progression of new asteroid discoveries since 1980. The years are noted in the lower left corner.

As the inner planets circle the Sun, asteroids light up as they’re identified like clusters of fireflies on a late summer evening. The clusters are mainly positioned along the outer edge of Earth’s orbit, as this is the field of view of most of our telescopes.

Once NASA’s WISE spacecraft begins its search around 2010 the field of view expands dramatically, as well as does the rate of new discoveries. This is because WISE’s infrared capabilities allowed it to spot asteroids that are composed of very dark material and thus reflect little sunlight, yet still emit a telltale heat signature.

While Scott’s animation gives an impressive — and somewhat disquieting — illustration of how many asteroids there are knocking about the inner Solar System, he does remind us that the scale here has been very much compacted; a single pixel at the highest resolution corresponds to over 500,000 square kilometers! So yes, over half a million asteroids is a lot, but there’s also a lot of space out there (and this is just a 2D top-down view too… it doesn’t portray any vertical depth.)

While most asteroids are aligned with the horizontal plane of the Solar System, there are a good amount whose orbits take them at higher inclinations. And on a few occasions they even cross Earth’s orbit.

(Actually, on more than just a few.)

Read: 4700 Asteroids Want to Kill You

An edge-on view of the Solar System shows the positions of asteroids identified by the NEOWISE survey. About 4700 potentially-hazardous asteroids (PHAs) have been estimated larger than 100 meters in size. (NASA/JPL-Caltech)

As far as how many asteroids there are… well, if you only consider those larger than 100 meters orbiting within the inner Solar System, there’s over 150 million. Count smaller ones and you get even more.

I don’t know about you but even with the distances involved it’s starting to feel a little… crowded.

You can see more of Scott Manley’s videos on YouTube here (including some interesting concepts on FTL travel) and learn more about asteroids and various missions to study them here.

Inset image: the 56-km (35-mile) wide asteroid Ida and its satellite, seen by the Galileo spacecraft in 1993. (NASA)