An interesting note right at the end, so in case anyone missed it: this same launch is believed to be the source of 5 titanium "spaceballs" that fell onto New Zealand in 1972.

While the odds are low of any space debris hitting land, it was the photo in this article that surprised me - I was thinking billiard ball size debris, not this - http://www.stuff.co.nz/the-press/4542804/Government-report-o...

> The balls, which had Russian markings, were used to pressurise fuel tanks or as stabilisation jets, the report states.

Spent a bit of time in the metal trade, sometimes various metals that can best be described as oddities from Sheffield would be heading south, one such time some metal pieces were on this lorry no bigger than a chunk of cheese or hash brown thats broken off, clearly its been part of a larger plate of metal, but its magnetic strength was so strong it needed a screw driver to leverage it off anything it was stuck to. Never seen anything as strong magnetically since, but it had became a sort of competition with people/visitors asked to try to pull it off what other metal it was stuck to.

> 20 kilogram, titanium sphere, > It is not something you would sell to a scrap dealer,'' he said.

The titanium being sold as scrap would come down in bars which had been angle-grinded all over to produce long metal splinters so that it could only be handled with a fork lift, the splinters would go through gloves if you tried to handle it. That shows to what lengths some scrap metals were "processed" in order to avoid being stolen.

Can anyone explain how it's possible for the apogee to reduce so much, while the perigee barely changes?

Wouldn't the air resistance that lowers the apogee also affect the perigee?

Or is it specifically because the object is being slowed at perigee, that the apogee lowers, while the perigee doesn't change much because the apogee is in vacuum?

If a chunk of Soviet space junk falls on someone's house, does the Russian Federation just shrug and say, "That was the USSR, bruh, sorry." They must have assumed responsibility for the Soviet space program, right? It's sort of like firing a bullet into the air... Doesn't matter how long it takes to come down, it's still your fault if it kills someone.

I'm trying to get my head around what sort of damage an object of this size travelling at terminal velocity would do.

Did anyone get when the ETA is for impact and predicted location?

How fascinating it would be to recover it for posterity.

Napkin math: earth's surface area is ~510 million square kilometers. The lander is described as fitting in a 1-meter protective shell. So we have a roughly 1 in 510 billion chance of standing in the lucky spot.

(This of course would only be accurate if all square meters of the earth's surface were equally likely to be hit. Not the case since the lander appears to be orbiting the equator.)

tl;dr on why its relevant:

„The reentry of the Kosmos 482 Descent Craft will not be your standard reentry. The Descent Craft was designed to survive entry through the dense atmosphere of Venus. It will therefore likely survive reentry into the Earth’s atmosphere intact and make a crash landing (it is extremely unlikely that the parachute system will still work after more than 50 years in space). This will therefore be a high-interest reentry.“

Is this the origin of the name for the film SPACEBALLS?

A water splashdown is the highest probability. But I think even with the 52 degree envelope, Russia is still probably the largest landmass in that envelope? So I take ironic pleasure knowing it’s more likely to smack back into Russia than any other country.

(I’m making an educated assumption about the geography, but could be wrong)

Think of a very very elliptical orbit, one that's nearly a line and consider what happens when you take a bit of energy off the orbiting object. At perigee, when the energy is almost entirely kinetic, you're mostly just changing the velocity, rather than altitude of the object. At apogee, when the energy is almost entirely potential, it's the other way round - the change is almost entirely one of altitude. This is further stretched by the much more 'visible' effect of potential energy changes on altitude than of kinetic energy changes on velocity.

the atmospheric drag at perigee happens perpendicular to the object speed, which is tangential to the gravity field, so the object doesn't get shifts on it's vertical speed, only it's energy, having less to convert in potential energy (i.e. apogee height)

in the thereabout of perigee you have two arms, one inbound and one outbound. the horizontal component of the drag for both is all in the direction against the travel and slow the craft without changing the vertical component of its speed

the vertical component of the drag (for as long as the craft has the energy to get's outside of the dense atmosphere) kind of cancels out, as the drag force inbound pushes against your down velocity vector and the drag force outbound pushes against your up velocity vector.

there is however a small energy loss due to the fact that the journey trough the atmosphere isn't perfectly simmetrical, since you're losing speed along all the way, the inbound leg is shorter than the outbound leg, causing the vertical component of the drag going outside to slightly exceed the component of the vertical drag coming in - so your perigee does change little by litte due this (and other more nuanced effects, but we're painting with a large brush here) - this asymmetry gets stronger the more you stay in the atmosphere and the furthest you dip in the dense area, until you ultimately don't have the energy to escape anymore.

the fact that the atmosphere isn't on/off like that but has a long boundary layer stretching far from the dense parts kinda complicates things a little more, because drag is applied the whole circle, but not by that much.

The rule of thumb you can use to make this intuitive:

A change in velocity at a certain point x on an orbit will change the entire orbit, except that orbit will still continue to go through that one point x.

So slowing down at perigee will not alter the perigee. (It is actually the most delta-v efficient way to lower the apogee.)

That is about it.