There’s been a lot of excitement about Mars recently, with the news that there’s liquid
water and everything.
But our next-door planet in the other direction will soon start to get its own share of attention.
Because the Akatsuki probe is about to make its second attempt at getting into orbit around
Venus.
For a planet that’s so close by, Venus is really hard to study.
Its thick clouds make it tough to see what’s going on down there, and landers tend not
to survive very long in the 460-degree temperatures.
We can send probes to visit, but the most recent one, the European Space Agency’s
Venus Express, officially ended its mission in December 2014.
So we haven’t had any active probes around Venus for about a year, and Akatsuki is looking
to close the gap.
But why is this the probe’s second attempt to study the planet?
Because the first time around, it missed. And ended up going around the Sun instead.
Launched by the Japanese space agency JAXA, the probe initially tried to enter orbit around
Venus back in 2010.
The plan was pretty simple, by spaceflight standards: they’d fire up the main engine
and adjust its course until it flew past Venus in just the right way to be captured by the
planet’s gravity.
But something went wrong. The engine, which was supposed to burn for 12 minutes, suddenly
stopped working after only 3.
The probe’s main engine had failed -- all that were left were secondary engines that
were just supposed to stabilize it.
But JAXA came up with a brilliant -- if risky -- Plan B: All they had to do was dump 65
kilograms of fuel, spend the next five years making tiny adjustments to the probe’s trajectory
-- and then make one really big adjustment at the end.
And that big adjustment -- a really long engine burn -- is coming up on December 7th, when
four of the tiny secondary engines will have to fire for 20 minutes straight.
If all goes well, Akatsuki will enter a very stretched-out orbit around the planet, taking
it within about 5,000 kilometers of Venus’s surface at its closest -- but, at its farthest,
a few hundred thousand kilometers away.
And instead of the 30-hour orbit that was originally planned, this one will take about
15 days, until another adjustment in March shortens it to 9 days.
If it works, Akatsuki will spend at least the next two years studying Venus -- mainly
monitoring its climate.
Which is really good news for researchers. Because they’ll still be able to get most
of the data they were originally looking for, and maybe even use the probe to finish what
Venus Express had started.
Using its cameras, Akatsuki will measure different layers of Venus’ clouds, and possibly complete
the map of its surface, using infrared light, that was started by Venus Express.
It should also still be able to detect whether there’s lightning in the clouds, and if
there’s a strong volcanic eruption, which would be exciting, because one of the planet’s
biggest mysteries is whether it has active volcanoes.
And! If you want to take a look at the planet while this is all happening, December 7th
will be a great time to do it!
Because the Moon and Venus will be only a fraction of a degree apart -- meaning that
you could cover the apparent distance between them with a pinky finger held at arm’s length.
The exact timing of this event -- known as conjunction -- depends on where you live,
but you should be able to see the pair almost anywhere in the world, just before dawn on
December 7th.
And if you live in Alaska or northwestern Canada, you’ll actually be able to see the
moon cover Venus!
Venus and the Moon tend to pass close to each other about once a month, but the last time
they were anywhere near this close was July -- and the next time will be in April.
So if you want to get a great look at Venus and a sliver of the Moon at once, December
7th is the morning to do it. You should even be able to get the two of them in the same
field of view with a pair of binoculars.
And don’t forget- that even though you can’t see it, Akatsuki is up there too. Go Akatsuki,
go!
Thanks for watching this episode of SciShow Space News, and thanks especially to our patrons
on Patreon-- you guys are amazing! If you want to help us keep making episodes like
this, just go to patreon.com/scishow. And don’t forget to go to youtube.com/scishowspace
and subscribe!