On Sunday June 28th, 2 minutes and 19 seconds after liftoff, the SpaceX Falcon 9 rocket exploded. It was carrying nearly 4 tons of supplies and experiments to the International Space Station and engineers still don't know why it happened. It was the second lost cargo ship in a row after the Soyuz's capsule in April. 

According to tweets from CEO Elon Musk, at first engineers thought that the problem had to do with a second stage liquid oxygen tank. Their theory was that it had too much pressure and it exploded. The Falcon 9 takes two stages to get to space. In the first one, it uses 9 engines to take care of most of the heavy lifting. Then those engines separate and a final engine burns fuel to get it to the right orbit. That's the fuel they thought was causing the problem, but then Musk tweeted that engineers weren't sure and were still combing through the data to figure out what happened in those last few milliseconds before the explosion. 

So as of Tuesday morning, all we know is that we don't know. The crew on board the ISS though will be fine. They have enough food to last them at least until October, and there are a bunch more launches scheduled for this summer. But as astronaut Scott Kelly pointed out in a tweet from space aboard the International Space Station, it's a reminder that space is hard. But that very hardness itself of space exploration is why New Horizons approaching Pluto is such a big deal. 

The probe will have only one chance to do a flyby of the dwarf planet and it's gonna be tough because we're not actually sure where Pluto is. Kinda weird to think about because Pluto is such an important part of our Solar System, of course, but it was just discovered in 1930's so we've only mapped part of its 248-year orbit, and come July 14th mission scientists don't know exactly where it'll end up. 

And to make the observations we really want, New Horizons needs to hit a very specific target about 12,000 kilometers from Pluto, which is very hard target to hit. Now, any last-minute adjustments to New Horizon's trajectory had to be made before July 4th so if the navigation team's predictions are off, they're just gonna have to try to change the timing of the observations so we still get some usable data. 

Meanwhile, the probe has already started making some discoveries. A few weeks ago, when it was still more than 30 million kilometers away, New Horizons took some pictures of Charon, Pluto's largest moon, and it turns out the moon has a strange dark cap. A brighter spot would've probably meant it was made of reflective ice, but scientists don't know what this darker region is made of. They should find out soon though, New Horizons will be taking lots of images as it zooms past, and the mission team is hoping to learn more about the terrains of Pluto and its moons, plus any chemical activity that might be going on there. 

Now Rosetta, the probe orbiting Comet 67P right now, has given us lots of new information too, mainly about ice. Small, bright, blueish spots scattered across the comet's surface are probably frozen water according to new research published in the journal 'Astronomy and Astrophysics'. There are about a 120 of these icy spots, each up to a few meters wide and as much as 10 times brighter than the rest of the comet.

Scientists figure they have to be made of water ice rather than other types of ice found on the comet, like carbon dioxide or carbon monoxide ice, because otherwise the amount of sunlight hitting the spots would've vaporized them quickly. 

They also think that some of the ice patches could have been revealed when cliff faces on the comet collapsed, which is actually connected to another weird feature of 67P that's been recently discovered - gigantic sink holes. Sink holes that are shooting out jets of dust. 

According to new research published this week in 'Nature', researchers think the pits, which can be up to 180 meters deep, form as the comet approaches the Sun when ice within the comet heats up and vaporizes. The vaporized ice leave behind holes in the rock, which eventually collapse, revealing more pockets of ice, which create the jets as they vaporize. 

And the Rosetta mission just got another 9 months to take advantage of the Philae lander's re-awakening so now it will continue through September 2016. So we have plenty of time left to learn more about this strange rubber ducky-shaped comet -- vaguely rubber ducky-shaped. 

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