Author Archives: Marcello

Charting the heavens with Gaia

Time is a child of the stars When Duke William IV of Hesse-Kassel – “William the Wise” – thought how to spend his spare time, he decided to follow his passion for the stars: he wanted to know exactly where the stars are in the night sky and whether they move and if so by how much. At the time – we are talking the 1580s here  – it was well known from ancient times as well as from the then-young field of astronomy that most species of light in the night sky are ‘fixed stars’. Despite their name, fixed stars do move across he sky, only this is a collective motion caused by the...

Jewels in the sky: Observing Mercury & Mars on 8 F...

Mercury is not an easy target to observe. The innermost planet in our Solar System is never further away from the Sun than 30 degrees. It is either trailing the Sun and disappearing below the horizon just after sunset or moving ahead of the Sun and visible just a short time before sunrise. One good opportunity to observe Mercury under good conditions will happen on 16 February when it reaches its maximum elongation (apparent angular distance) of 18 degrees. However, a much more spectacular view (weather permitting!) will be offered on the Friday before, on 8 February, when Mars and Mercury will be separated in the sky by only 20 arc minutes...

Lunar Surprises

Lunar exploration is struggling with the prejudice that we know all about the Moon – far from it! There are new scientific findings based on the analysis of Apollo samples that call in question the generally accepted theory about how the Moon formed. Also, scientist from Europe and in the US have just started to investigate the geochemistry of the Moon. ESA has proposed a highly interesting lunar lander mission, which was unfortunately rejected by its member states. The Lunar Lander was supposed to test how sustainable exploration can take place on the lunar surface. It is important that European states do find a possibility of a substantial lunar mission in the...

Space exploration bashing – gone wrong

Dear Friends of Space Exploration, Before I continue my (admittedly delayed) mini-series on Alpha Centauri B b, I have to blog about a marine biology talk at the TED conference I came across this morning on the bicycle. I regularly use the 20-min. bike trip to work to listen to TED talks, which nicely fill that time span. Most of them are extremely inspiring. Just have a look/listen in at: “TED – Ideas Worth Spreading”. This morning, however, I almost fell off the bike by an otherwise well-presented talk on the census of marine life by oceanographer Paul Snelgrove (here is the link). First, he is bashing space exploration by saying: “This...

What is an UNconference?

“Why should we travel to other stars?”, asked one of the 60 participants of the “unconference” dubbed SpaceUp last Saturday, 27 October 2012, in Stuttgart. The question was raised after a presentation from the brand-new Institute for Interstellar Studies (www.I4IS.org). The mission of the institute is to promote the possibilities to explore, communicate with and even travel to planetary systems in our cosmic neighbourhood. The presenter, Chris Welch, a British professor teaching at the International Space University in Strasbourg, had no difficulties in answering: “Eventually the Sun will expand and burn the Earth completely. This will not happen in 40 weeks nor in 40 years, but it will happen at the end of...

Centauri B b – A new window for discovery

Last week, the European Southern Observatory ESO announced the finding of an Earth-sized planet around the nearby star Alpha Centauri B. Based on measurements by spectrograph, which registers the exact location of absorption lines in the stellar spectrum as a function of time, the research team around Xavier Dumusque of the Geneva Observatory could determine the radial motion of the star as seen from the Earth. A somewhat tedious process of removing background effects from the motion of the observer (Earth rotation, Earth orbit around the Earth-Moon centre of gravity, Earth orbit around Sun), as well as any convective motion of the hot gases in the star’s outer shell yields the proper motion of Centauri...

A Man – and an equation

If there is a man who is at the heart of rocket science, it is Konstantin Tsiolkovsky. The man has quite an unusual professional background, which is not surprising given the fact that in the late 19th or early 20th century space exploration was more a subject of fiction literature (a prominent writer of which was Jules Verne, who deeply influenced Tsiolkovsky) than reality. It was said of Tsiolkovsky that he was a bit eccentric but withdrawn. He did not excel in his studies as a young man, but the fascination of the possibilities of space travel kept him working in the field. In the early 20th century he taught math in...

SpaceX

We have to congratulate SpaceX for another amazing achievement as they launched the first commercial supply mission to the ISS, which launched today at 02:35 CEST (check out the launch video via YT). Even with an engine shut off in the most critical phase of the mission (around max Q – the point during ascent when aerodynamic forces are at the maximum), the capsule reached its planned orbit, demonstrating the robustness of the Falcon 9 launch vehicle. The engine failure is, however, bad news for the auxiliary satellite payload by OrbComm. Their satellite missed the ISS ‘safety gate’, a window in the orbital elements (trajectory calculation) that ensures long-term collision avoidance with the...

The infinite value of space science

When working in the space field, we quite often get asked: how can you justify the expenses of space research? It is funny that we get this question more often than other researchers, e.g. particle physicists or biomedical researchers, in whose fields more money is spent globally. When thinking about what to reply to this – in any case justified – question, I thought about our recent experience of the Venus transit. I was not lucky enough to witness it myself, so I read the articles that are around on the web. I found one that described the science that was done at the 2004 transit (remember, they always come in pairs, eight years...

The best spot for space astronomy

Editor’s note: Today’s post was contributed by Markus Landgraf from the Mission Analysis Section at ESA’s ESOC establishment, Darmstadt, Germany. It highlights the detailed assessment of options, scientific and practical factors that must be taken into account before any mission can be flown. If we are to explore not only our solar system, but also the cosmos in more general, we have to rely on telescopes to collect starlight. For most applications this is most efficiently done outside the Earth’s atmosphere and thus follows the need for installation and operation of space telescopes. Globally speaking Europe leads astronomy research, not only due to our history, but also due to the missions currently...