We’ve all been there. You’ve put something down, and now you can't find it – it’s like it disappeared into thin air. But earlier this month, a NASA tool bag literally did fly off into a vacuum during routine checks aboard the International Space Station (ISS).
The tool bag has been orbiting Earth for the last few weeks, having been photographed by Japanese astronaut Satoshi Furukawa a few days after it escaped – as imaged above.
Now, the tool bag has become the latest in a series of celestial (or, rather, mechanical) wonders you can watch as they pass by in the night sky.
But where can you see it – and when? How can you spot it as it passes overhead? This page will tell you everything you need to know.
When will the tool bag in space be visible?
The NASA tool bag will be visible to people in the US and UK several evenings this week (21-25 Nov). It’s travelling fast, so it will only be visible for a couple of minutes in the sky.
You may have another chance to view the tool bag later this week, but as the tool bag descends closer to Earth’s atmosphere it could burn up at any moment.
In the UK, the tool bag is likely to be visible between 7:10pm and 7:20pm GMT this evening (22 Nov).
If you're viewing from the USA, the tool bag will pass by on its first leg in the late afternoon of Wednesday 22 November – but some viewers will have to wait until the second leg, after the Sun has set, to see it. Watchers in the northern states of the USA and in Canada may be more lucky.
In the USA, observers in the state of Oregon will have the best chance of spotting the tool bag in the skies over the coming days, Dr Darren Baskill, astronomer lecturer at the University of Sussex, tells BBC Science Focus.
"The bag will be flying overhead around 5.25pm on Wednesday 22nd and 6.15pm on the Thursday the 23rd, and at just after 7pm on Friday the 24th, with the International Space Station following it about 20 minutes later on all of these occasions."
As the bag is on the same path as the ISS (though ahead rather than behind it) you can track the space station’s trajectory to help you decide whether it’s time to stand outside.
But the more time passes, the greater the distance between the tool bag and the ISS. According to Baskill, "now that the crew lock bag has separated from the International Space Station, its orbit has changed from that of the ISS. Over the 20 days since the bag was accidentally released, it has slowly drifted away – and is now some 6km (3.7 miles) closer to the Earth."
Baskill adds that the tool bag is currently 22 minutes ahead of the space station.
Where to see the NASA tool bag
If you're in Europe, you're in the best place to see the tool bag, says Baskill. That's because the bag (and the space station trailing behind it) are flying over the continent at dusk, when the darkness makes it easier to see.
"For the United States however, only the northwestern states are fortunate to have the pair flying overhead at dusk," Baskill says. "It is much lower in the sky the further east or further south you travel, with it being impossible to spot from the southern states."
Baskill recommends checking websites like NASA's Spot the Station for accurate times tailored to your location.
In the UK, each evening the tool bag will be passing overhead on a trajectory spanning from southern Wales to the east coast of England. It will move through the skies north of Cardiff, through the Cotswolds, and over the suburbs of Northern London – all in the space of about five minutes.
On 23 Nov, the tool bag will pass over the UK a second time, this time starting on the north coast of Devon, moving south through Southampton, and disappearing off the coast between Portsmouth and Brighton.
On 24 Nov, the tool bag will complete three trips over the UK, following similar paths to those above – but going straight through inner London on its first leg.
In North America on 22 Nov, the tool bag will appear off the coast of California before moving north through eight more states in an arc heading northeast. However, for several of these dates the daylight will obscure any view of the toolbag. It will then travel over Canada, passing through Ontario before disappearing over the state of Quebec.
Most days the tool bag will return for a second and even a third show just a few hours later, but sticking mostly to Canada on these.
The website N2YO.com is currently tracking the tool bag if you want to follow it – but make sure to look up from your screen in time for the show.
How can I see the NASA tool bag?
The tool bag may be small – and 250 miles (402km) away – but you may be able to spot it if you know how.
"To see the bag, or any specific satellite, you need a bit of luck!" Baskill says. "The bag has to fly overhead during dawn or dusk, when sunlight can illuminate the bag but the Sun has set over your location so that the sky is darker."
Given that the tool bag is made of a highly reflective material, it will resemble a glowing star moving slowly across the sky. It will come from the west – so make sure you’re looking in the right direction.
You might struggle to see this with the naked eye, but with the help of binoculars or a telescope you'll have a better chance.
That's because it's much smaller than the ISS, which you can see with your naked eye thanks to its football field-sized solar panels – says Baskill.
How do I spot the International Space Station?
You can track the ISS on NASA’s live tracking map. The space station is due to pass through the UK a bit later than the tool bag – which is rapidly moving away from it.
The ISS is visible with the naked eye, and completes orbit every 96 minutes. "This is quite standard for a low Earth orbit," says Baskill. "Any slower than this and it would fall towards the Earth, and any faster and it would move away from the Earth."
Most evenings this week, the ISS will be on a low pass – meaning when it passes overhead it will be low in the sky. So for best viewing opportunities, try to find somewhere with a clear horizon.
You’ll also have a much better chance of viewing if there are fewer clouds in your area this evening.
How did the tool bag get lost?
The tool bag was lost when NASA astronauts Jasmin Moghbeli and Loral O'Hara were carrying out repairs on the ISS, including replacing the hardware that supports the station’s solar arrays. They put it down and didn’t notice it slip away – and when they went back to look for it it was gone.
But you can see the moment it happened in NASA’s recording of the livestream below (at 4:03:46).
About our expert
Dr Darren Baskill is an outreach officer and lecturer in the department of physics and astronomy at the University of Sussex. He previously lectured at the Royal Observatory Greenwich, where he also initiated the annual Astronomy Photographer of the Year competition.
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