Each galaxy lives within its own three-dimensional halo of dark matter whose gravitational field corrals the stars within it. Without the stars, the halo would still be there, albeit invisible to our eyes; but if the halo vanished, the stars would scatter into the depths of the universe – just as a Christmas tree remains a tree with or without the pretty lights. Whereas without the tree, the lights would merely be a puddle of colour on the snowy ground.
This is the week the Nobel Prizes are announced, and today is the day (at least in New Zealand; first place in the world to see the light, as the tourist people say) the Physics prize is announced. And this year the odds-on favourite will be LIGO and the discovery of gravitational waves.
NASA has an undoubted ability to sell a story, and it has been making the most of the anthropomorphic appeal of this brave little $3 billion, 5 ton, plutonium-powered spacecraft on its two-decade mission. But the hype is not misplaced: Saturn has a key place in the evolving human understanding of the cosmos.
As you can guess from the title, The First Three Minutes tells the story of the moments following the Big Bang. The early universe sets the stage for the development of the cosmos we observe today, and the Cosmic Microwave Background is a key link between the distant past and the present day.
But despite being commonplace, spaceflight is still far from routine. In fact, in the six decades since the Soviet Union started the space race, just eleven nations and the European Union have achieved indigenous launch capability, sending a locally developed rocket into orbit.
Elon Musk knows how to make a splash, and today he outlined his plan to turn humanity into a "multiplanetary species". Musk painted a picture of a future where travel to Mars was downright cheap, with tickets costing as little as $200,000, the median price of an American home. So is this possible? I have no idea, but it makes for a great Fermi question, a problem so fuzzy and incomplete that educated guesswork is the only way forward.
Last Friday, work kept me late at the office. It was a clear and cloudless night and the stars were out as I biked home in the dusk. And as my pedals turned, the night sky wheeled more slowly above me.
This week, the University of Auckland (where I work) announced it is joining the Large Synoptic Survey Telescope collaboration. So what is the LSST, what will it do, and why are we so excited about it?
As an astrophysicist, I hope that the TMT will be built – it is an astonishing instrument, big enough to catch the the light from the first generation of stars to be born after the Big Bang, and sharp enough to make images of planets around other suns. However, I also hope that my community can do this without riding roughshod over a people who claim Mauna Kea as their own
Bolides are like lotteries – the chances of you winning the big prize are small, but the chances that someone, somewhere will win are pretty good. So if you missed last night's fireball, you will wait a long time before seeing another one.
Astrophysicist Beatrice Tinsley (1941-1981) was once a leading candidate for the "Most Important New Zealand Scientist You've Never Heard Of Award", but has been largely eliminated from consideration by a stage play, having a mountain named after her, and a full-length biography.