Happy Thought for 9 May 2025

Have a Happy Thought: 

Looking up at the sky is a wonderful way to feel a sense of awe.

This weekend, though, you may feel some slight apprehension, as we all wait for a probe to fall to Earth. This probe was intended for Venus, sent by the USSR in 1972. But the rocket taking it out of our upper atmosphere failed, so instead of heading to Venus, this probe has stayed in an odd Earth orbit for the past 53 years!

All good things must come to an end...

or is it “What goes up must come down”?

Either way, this probe’s orbit has decayed enough recently that everyone watching it is fairly sure it’s going to fall back to the Earth’s surface this weekend.

Here’s a mockup of the thing we’re all looking for: (It’s not a picture of the real thing, because of secrecy still hanging over from the Cold War. This one was built by NASA trying to reverse-engineer the lander.

Image: mockup of The Kosmos 482 Venus lander. (Credit: NASA) It is estimated to be about 1m diameter, and weigh about 500 kg.

There is a lot of uncertainty, but right now it’s predicted to land on 10 May 2025, 7:34 UTC ± 10.6 hr. In other words, that is anywhere between Saturday morning 9am through to Sunday at 6am, New Zealand time. Or, any time from Friday 2pm to Saturday 11am, US Pacific (PDT) time.

Why so much uncertainty in the timing? Well, it largely comes down to... space weather! If there’s a lot of solar activity, that basically makes the Earth’s atmosphere... stickier. And that will slow down the spacecraft more, and make it plummet to the surface earlier. Calm weather will keep it sailing for longer.

But where, you ask? Well, it all depends on the when. Basically, it will fall somewhere along this blue line, which is the track this traces above Earth while in orbit. 

Image source: https://sattrackcam.blogspot.com/2025/04/kosmos-842-descent-craft-reentry.html?m=1

As you can see, there is very little chance of this orbiter landing in New Zealand.

But... part of it already has!

Yep, back in 1972 when this was first launched, parts of the rocket, probably pressure gas tanks from the control system, landed on New Zealand’s South Island, with somewhere between five and nine large metal spheres landing in various paddocks. One farmer recounted picking up the ball from his paddock, and holding it in his lap to drive it back to his farmhouse. When the authorities arrived and speculated that anything that fell from the sky could be radioactive, well... all's well that ends well?

Image: Ashburton farmer Denis O’Sullivan with the 20-kg titanium sphere. He was 17 in 1972 when this dropped onto his farm.

Luckily for him, and all of the others who found these, it turns out the spheres were not radioactive, and they remain* in farmers’ possessions, with one in a local museum.

*(One of the spheres ... ended up locked in a cell in the Ashburton Police Station. “This mystery object… has committed no crime other than its persistent refusal to identify itself,” the Christchurch Star reported.)

The USSR never accepted responsibility, or even claimed ownership of these spheres, but much detective work leaves little doubt as to their origin.

The only remaining question is... where will the Kosmos 482 craft itself land? And for that, we wait and watch the skies.

PS: it’s really likely that this craft will “touch down” in an ocean, but you might be able to see the streak of it coming through the atmosphere, if you’re lucky!

Read more local NZ reporting about the 1972 Ashburton event, including some great pictures, here: https://www.odt.co.nz/star-news/star-districts/star-mid-canterbury/really-bizarre-day-strange-metal-sphere-fell-space

Also this great account:

https://pauldmaley.com/sd3/ scroll down to 1972: COSMOS 486 ROCKET DEBRIS

And of course https://www.nzgeo.com/stories/the-space-balls-are-coming/