Space

Starburst galaxies are where stars are forming at such a breakneck rate that the galaxy is eating up its gas supply faster than it can be replenished. There are several different factors that can lead to such an ideal environment in which stars can form at such a rapid rate. Crucially, there has to be a sufficiently massive supply of gas. This might be acquired in a number of ways -- for example by passing very close to another galaxy, in a full-blown galactic collision, or as a result of some event that forces lots of gas into a relatively small space. Star formation leaves some clues behind…

This evening I am blogging from a residence in Sesto val Pusteria, a beautiful mountain village in the Italian Alps. I came here for a few days of rest after a crazy work schedule in the past few days -the reason why my blogging has been intermittent. Sesto is surrounded by glorious mountains, and hiking around here is marvelous. But right now, as I sip a non-alcoholic beer (pretty good), chilling off after a day out, my thoughts are focused 500,000,000 kilometers away.As an amateur astronomer since the age of seven, I have always loved to watch the night sky and its treasures. Nowadays I do…

The umbrella term for the 68 percent of the universe that we can't detect and know nothing about has been given the umbrella term "dark energy." Like wormholes 30 years ago, it is more MacGuffin than science. You could call it aether or magic or any deity name and be just as valid. But inference says something, or a variety of somethings, must be causing the universe to expand when gravity says it should contract. So dark energy it is. Except maybe it isn't.  Our universe was formed in the Big Bang, ~13.8 billion years ago, and has been expanding ever since, according to Hubble's law,…

This is an update to my article: How A "Dwarf Planet" Gas Giant Could Challenge IAU Definition - Pluto, Ceres, Haumea Etc Can All Be Planets. That article pointed out that we could discover a gas giant in our own solar system that satisfies the IAU definition of a "dwarf planet" as it wouldn't clear its orbit if it was far enough away. First, I should have pointed out there that the WISE search has not ruled out gas giants in the remote parts of our solar system. It ruled out a Saturn sized gas giant out to 10,000 au and a Jupiter sized gas giant out to 26,000 au, but the hypothetical Nemesis…

I think the chances of the SpaceX mission around the Moon going ahead on schedule in 2018 is tiny. But on the remote chance it does, I would not fly on that mission, if you paid me a billion dollars. The problem is that they have to rely on many innovations working just right that are hardly tested. Their current Dragon spacecraft is only rated for re-entry from LEO (Low Earth Orbit) and not for the much faster re-entry from a trip around the Moon. That’s why they plan to use the larger Dragon 2 which has its first flight in 2018. If we go by Elon Musk’s suggested timeline, this flight around…

I think the chances of the SpaceX mission around the Moon going ahead on schedule in 2018 is tiny. But on the remote chance it does happen, I would not fly on that mission, if you paid me a billion dollars. The problem is that they have to rely on hardware that is hardly tested in space at all. They are depending on a spacecraft which will have its first flight in 2018, the Dragon 2. Their current Dragon is only rated for re-entry from LEO (Low Earth Orbit). Only the Dragon 2 has a thick enough aeroshell to handle the much higher speed of re-entry into the Earth’s atmosphere from the Moon.…

SpaceX doesn’t have the capability yet. In this plan, they are depending on a spacecraft which will have its first flight in 2018, the Dragon 2. That’s because they need to be able to do a re-entry from the Moon, which is much faster than from LEO (Low Earth Orbit). Only the Dragon 2 has a thick enough aeroshell to handle that speed of re-entry into the Earth’s atmosphere. They are also depending on the Falcon Heavy to launch it, a rocket that will fly for the first time perhaps in late 2017. The Falcon 9 “full thrust” can launch a Dragon 2 to LEO but not around the Moon. So it would be the…

SpaceX doesn’t have the capability yet. In this plan, they are depending on a spacecraft which will have its first flight in 2018, the Dragon 2. That’s because they need to be able to do a re-entry from the Moon, which is much faster than from LEO (Low Earth Orbit). Only the Dragon 2 has a thick enough aeroshell to handle that speed of re-entry into the Earth’s atmosphere. They are also depending on the Falcon Heavy to launch it, a rocket that will fly for the first time perhaps in late 2017. The Falcon 9 “full thrust” can launch a Dragon 2 to LEO but not around the Moon. So it would be the…

Ethan Siegel has just written an article, "The Science Has Spoken: Pluto Will Never Be A Planet Again", so this is a response to it. I'll argue that far from "story over", actually we could make a discovery tomorrow that would turn the whole thing on its head and make their definition untenable.  This will become particularly acute if we ever find a gas giant in the outer reaches of our solar system, too far away to clear its orbit. And we could find such a planet. The WISE survey only ruled out Saturn sized planets out to 10,000 AU and Jupiter sized ones out to 26,000 au. We could have…

Yes it would be an exciting day when the first human steps on the surface of Mars, and a matter of prestige for those concerned. This is something I have read about since a child, and would be as excited as anyone. But it might quickly change to dishonour if it is found that they introduced reproducing Earth micro-organisms to Mars. They might enter the history books as the people who contaminated Mars irreversibly. To dramatize the idea, here are a series of fake newspaper stories in a (hopefully) "alternative future" in which humans accidentally introduce Earth life to Mars, then regret…