It's great to have access to “the Universe under one roof”. When European Astrofest comes to the Kensington Conference Centre in London, it saves many light years of travel.

Looking, learning, shopping
There were three floors of astronomy-related items to buy, exhibitions, and people to talk to. Universities offered distance learning courses. You could join an astronomical society or buy some of their attractive goodies. There were books galore, some beautiful jewelry based on nebulae, and of course telescopes, binoculars and all the accessories needed for observing.

Conference
The conference program's four sessions were under the direction of two chairpersons. Stuart Clark is an author and prize-winning journalist. Lucie Green is a professor, solar astronomer and television presenter. Here are some highlights.

Dust
Dust is the bête noire of astronomy. Cosmic dust particles are about the size of smoke particles, and obscure the view in the same way. The Milky Way would look a million times brighter without the dust.

But dust fascinates Haley Gomez of Cardiff University in Wales. It's one of the raw materials for making stars and other celestial objects. It's everywhere, yet no one really knows where it came from. However Gomez has been involved in research that shows supernova explosions produce prolific amounts of it. This is a fairly recent discovery, because in order to study cosmic dust you need to observe it in the infrared light that our atmosphere blocks. Telescopes like the Herschel Space Observatory are essential.

Revealing the cosmos
We see the heavens via the electromagnetic spectrum, which is light at various wavelengths. Megan Argo from Jodrell Bank Centre for Astrophysics explained that different wavelengths give different kinds of information. Looking at a galaxy in visible light shows us the stars, but not baby stars. They're hidden in thick dust. Infrared light penetrates the dust to expose stellar nurseries. Radio astronomy detects traces of past events, exposing historical information about the evolution of a galaxy.

There is also matter that electromagnetic radiation can't detect – dark matter. Andrew Pontzen of University College London says there seems to be over five times as much dark matter as the everyday matter we're used to. Although it's invisible, it has gravitational effects on matter that we can see.

There's no way to see the Universe soon after the Big Bang because for its first 380,000 years it was opaque to electromagnetic radiation. If a telescope could see far enough to view that early time, we couldn't see anything. However if we could detect gravitational waves, as described by Einstein, they could tell us something of the infant Universe. Michèle Heurs of the Max Planck Institute for Gravitational Physics works on ultra-stable laser systems for gravitational wave detectors. She thinks we're close to being able to make measurements, saying resolutely, “We have the sensitivity to measure stuff, and stuff will be measured.”

Space missions
John Spencer, deputy leader of the geology and geophysics team on the New Horizons Pluto mission, described the background and history of the mission. Last year the world was enthralled by the wonderful images of Pluto. So everyone laughed when Spencer reminded us of some of the best images available before the fly-by. One was this Hubble Space Telescope image of Pluto.

Matt Taylor is the man who landed a probe on a comet – or, as the Rosetta mission's Project Scientist, was part of a team that did. He gave a brief recap of the mission, but his view of the project from the inside was fascinating. Someone commented, “It felt like you were there.” ESA approved the project in 1993, so some people have spent a long time working on it, and it's continued for long enough to involve a second generation of scientists.

Mark McCaughrean, a Senior Scientific Advisor to the European Space Agency (ESA) spoke about several missions. One was LISA Pathfinder launched in December 2015. It's testing technology for a gravitational wave observatory in space. The Gaia mission, launched in 2013, doesn't get much publicity because it doesn't take pictures. But its mission is to provide data for a 3D map of the Galaxy. It's measuring the positions of around a billion stars with a precision equivalent to locating a human hair 2000 km away.

In a class of their own
Two unusual presentations were given by Brian May – professional rock legend and amateur astrophysicist – and Allan Chapman – highly knowledgeable Oxford University historian of science.

Brian May had the entire audience (around 800 people) equipped with special 3D glasses for his brief history of stereoptics. He supported his argument for greater use of stereo imagery in astronomy with some examples of surface features on Mars that were hard to interpret until transformed by 3D.

Allan Chapman's subject was Robert Hooke (1635-1703), a superbly talented polymath. He was the first to draw an individual lunar feature, which was included in his great work Micrographia. You can see his drawing compared to a modern photograph of Hipparchus Crater. Hooke also carried out a series of experiments to try to understand lunar craters, perhaps making him the first planetary scientist.

Note: I attended Astrofest as a guest of the organizers Astronomy Now magazine. Many thanks to them.