Two of the most important substances known to humanity and some of my personal favorite substances have just been discovered in space for the first time. And they've been discovered on two different comets.

In the past couple of weeks, scientists announced that comet 67P, good ol' Churyumov-Gerasimenko, has oxygen, while another giant space ball, comet Lovejoy, has alcohol. Doesn't comet Lovejoy sound like a good name for a cocktail? 

Comets, as we've talked about before, spend most of their time far from the Sun; either way out in the Kuiper Belt, beyond Neptune, or in the Oort Cloud on the outskirts of our Solar System. But, every so often, a comet will get to the part of its orbit where it flies closer to the Sun, giving us the opportunity to study it up close.

Over the years, we've studied the comas, the cloud that surrounds the nucleus of a lot of comets. So we know that usually the gases in there are about ninety-five percent water, carbon monoxide, and carbon dioxide. Comets have all kinds of other molecules, too. And some of them are complex organic molecules, meaning that they have carbon and hydrogen in them.

In July, for example, the Philae lander found evidence of sixteen different organic compounds on comet 67P. But one thing we've never found in a coma is molecular oxygen, O₂ - at least until now. And the discovery is raising some questions about what the Solar System was like when comets formed in the first place.

Over the course of seven months, 67P's coma had on average 3.8 percent as much oxygen as it had water vapor. From September 2014 until March 2015, Rosetta orbited the comet, taking measurements at different parts of the coma which had different concentrations of gases.

To figure out where the oxygen was coming from the researchers compared its concentration in those different places to other compounds like carbon monoxide, nitrogen and water vapor. They found that the changes in oxygen's concentration generally corresponded to changes in water vapor. Meaning that as the comet formed, those two substances were probably incorporated into the nucleus together.

But if that's the case, which it seems to be, then the scientists are stumped because none of the models for comet formation say that there was any O₂ that could have been captured by a comet. So it's weird. But that's why we keep studying comets. They help us discover what the Solar System used to be like. And in this case 67P seems to be telling us that we have some rethinking to do.

Of course, 67P isn't the only comet that's brushed by Earth lately. Comet Lovejoy passed closest to Earth back in January, and while we didn't send any probes out to meet it, scientists were carefully observing it.

Using a radio telescope in Spain, an international group of astronomers analyzed the microwave radiation coming from the comet. Because when molecules in the comet absorb energy from the Sun, they emit radiation at specific frequencies. And when the researchers mapped comet Lovejoy's data into the known frequencies for certain molecules, it matched the signatures of 21 different molecules including for the first time ever ethyl alcohol. Not methanol, the type of alcohol we found on comets before, but ethanol, the type of alcohol we drink.

According to the lead author on the paper, it was releasing as much alcohol as you'd find in 500 bottles of wine every second. So cheers, Lovejoy!

But researchers also detected another molecule that's never been found in a comet before - glycol-aldehyde, the simplest molecule related to sugar. Figuring out what is in comets is important because about 3.8 billion years ago the Earth was getting bombarded by comets, which might have left some of those more complicated molecules behind. 

So some scientists think that's where Earth got its complex molecules, which could have provided some of the ingredients life needed to evolve.

Slowly, as more comets swing by the Earth and we get to learn more about them, we're piecing together a picture of what the Solar System was like when it formed. But we might also be discovering a different part of history - what Earth was like when life formed. And it could turn out that those festivities were pretty well stocked with oxygen, alcohol and the building blocks of sugar.

Sounds like the makings of a pretty good cocktail.

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