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#128 - Ethan Siegal - Black Hole Pictures

This week's guest Ethan Siegel talks Black hole pictures before they were even out.

Ethan R. Siegel is an American theoretical astrophysicist and one of our favourite science writers, his blog Starts With a Bang is on ScienceBlogs and also on

#OTD 12 April 1961 - Yuri Gagarin's first flight into space - Vostok 1

12 April 1817 - Charles Messier died 202 years ago!!

The French astronomer who published the most famous astronomical catalogue consisting of 110 nebulae and star clusters, which came to be known as the Messier objects. The purpose of the catalogue was to help astronomical observers, in particular comet hunters like himself, distinguish between permanent and transient visually diffuse objects in the sky. Messier discovered 13 comets, and M87

Space News. The NASA Innovative Advanced Concepts (NIAC) program. The program will fund 18 studies to determine the feasibility of early-stage technologies that could go on to change what’s possible in space.

Like Micro-Probes Propelled and Powered by Planetary Atmospheric Electricity (MP4AE): Similar to the ballooning capabilities of spiders, these floating microprobes use electrostatic lift to study planetary atmospheres Lunar-polar Propellant Mining Outpost (LPMO): Affordable lunar pole ice mining for propellant production Solar Surfing: A materials-science study to determine the best protective materials to enable heliophysics missions closer to the Sun

Picture by Frank Olsen via Facebook

The atmosphere over northern Norway appeared quite strange for about 30 minutes last Friday when colorful clouds, dots, and plumes suddenly appeared. The colors were actually created by the NASA-funded Auroral Zone Upwelling Rocket Experiment (AZURE) which dispersed gas tracers to probe winds in Earth's upper atmosphere. AZURE's tracers originated from two short-lived sounding rockets launched from the Andøya Space Center in Norway. The harmless gases, trimethylaluminum and a barium/strontium mixture, were released into the ionosphere at altitudes of 115 and 250 km. The vapor trails were observed dispersing from several ground stations. Mapping how AZURE's vapors dispersed should increase humanity's understanding of how the solar wind transfers energy to the Earth and powers aurora.

THE PHOTON: Rocket Lab is getting into the satellites business, making them in addition to launching them.

Peter Beck, Rocket Lab’s CEO. “It always seemed bizarre to me that you would have a [spacecraft] that has all the same components as the satellite literally six inches away from each other,” Beck tells The Verge, referring to the Electron kick stage. “But we wouldn’t talk to each other and we’d just push each other off, and that would be the end of it. It just seemed bizarre that we would do that rather than actually just combine everything into one unit.”

The world’s first collision experiment with an asteroid! On 5 April 2019, Hayabusa 2 released an impactor and created an artificial crater on the surface of Ryugu First, the probe lowered itself from a parking altitude of 20 kilometres down to 500 metres above the asteroid’s surface. From there it shot an kenetic impactor, Small Carry-on Impactor (SCI). After partially ascending, it then released a second device carrying a camera DCAM3 to film the impact. The stuff will be gathered up at some point and returned to earth.

Space Word of the week Angular diameter Measurement describing how large a sphere or circle appears from a given point of view Imagine a a pair of compasses, or dividers, you know a compass the technical drawing instrument that can be used for drawing circles at school. Well imagine holding the top against your eye and closing them round an object like the moon. The angle that the two halves makes would be say 0.48 degrees. 360 degrees is very similar to a year (not by coincidence really) so think of a clock instead of a circle. the decimal place can be replaced by minutes and seconds, 1 degree is 60 minutes and 1 minute is 60 seconds. So 0.48 degrees is more like 29 arc-minutes 20 arc-seconds. In astronomy, the sizes of celestial objects are often given in terms of their angular diameter as seen from Earth, rather than their actual sizes. Since these angular diameters are typically small, it is common to present them in arc-seconds

Astronomers use their hands at arms length to measure approx angular diameter. The nail of you little figure will cover the moon as it is twice as big at 60 arc minutes or 1 degree. An arc-minute is approximately the resolution of the human eye. 1 arc-second would be like a coin 2.5 miles away very tiny. Hubble Space Telescope has calculation resolution of 0.05 arc-seconds and actual resolution of almost 0.1 arc-seconds, which is close to the diffraction limit Pluto is 0.06 Arc seconds, hence we had to send a probe.

Charles Messier discovered M87 in 1781, the object was included as NGC 4486, in the New General Catalogue of nebulae and star clusters assembled by the Danish-Irish astronomer John Dreyer in the 1880’s, which he based primarily on the observations of the English astronomer John Herschel In 1918, the American astronomer Heber Curtis of Lick Observatory noted M87's lack of a spiral structure and observed a "curious straight ray ... apparently connected with the nucleus by a thin line of matter." The ray appeared brightest near the galactic center.[14] The following year, a supernova within M87 reached a peak photographic magnitude of 21.5, although this event was not reported until photographic plates were examined by the Russian astronomer Innokentii A. Balanowski [fr; ru] in 1922.

supergiant elliptical galaxy in the constellation Virgo. One of the most massive galaxies in the local UniverseThe MASSIVE galaxy in the virgo super cluster called M87 is 120 light years accross still 7 arc Minutes, that’s the size of the whole smudge, about a 5th the size of the moon, with a very bright, 45-arcsecond core. However as it is nowhere near as bright as the moon you can’t really see it with out some opitcal help. M87 it self is massive but it has a beast in the middle 6.500,000,000 times the mass of the sun. Considering it’s mass it’s small but it is about 2 billion km or about 7.3 micro arcseconds, Sagitarrius A* has an overall angular size for the source of 50 μas. At a distance of 26,000 light-years, this yields a diameter of 60 million kilometers it’s size about the orbit of mercury If earth was the size of a helium atom, then M82 would be 25metres across, but 7000 miles away. The black hole would be only 0.004mm ...and that is why we must talk about it. The people who did it The breakthrough image was captured by the Event Horizon telescope (EHT), a network of eight radio telescopes spanning locations from Antarctica to Spain and Chile, in an effort involving more than 200 scientists. Sheperd Doeleman, EHT director and Harvard University senior research fellow Katie Bouman, an MIT graduate. 3 years ago she led the creation of a new algorithm to produce the first-ever image of a black hole we are seeing today. Ziri Younsi, a member of the EHT collaboration who is based at University College London. “The black hole is not the event horizon, it’s something inside. It could be something just inside the event horizon, an exotic object hovering just beneath the surface, or it could be a singularity at the centre … or a ring,” “It doesn’t yet give us an explanation of what’s going on inside.” Heino Falcke, chair of the EHT science council, who is based at Radboud University in the Netherlands, said: “The big question for me is whether we’ll ever be able to transcend that limit. The answer may be maybe not. That’s frustrating but we’ll have to accept it.”

A defining feature of the images is an irregular but clear bright ring, whose size and shape agree closely with the expected lensed photon orbit of a 6.5 billion solar mass black hole

The collaboration is still working on producing an image of the Milky Way’s black hole. “We hope to get that very soon,” said Doeleman.

Space fact Is the earth losing or gaining weight? Earth gains about 40,000 tonnes of space dust every year Earth gains about 160 tonnes of mass a year because the global temperature is going up: Losing weight Earth's core loses energy over time. 16 tonnes are gone every year. 95,000 tonnes of hydrogen

1,600 tones of helium escape Earth every year. But also The asteroid that struck near Chicxulub some 65 million years ago choked out most life forms, including the giant dinosaurs that had roamed Earth for some 135 million years before disappearing around that same time. Chicxulub impact may have launched 70 billion kilograms of rock into space, of which 20,000 kilograms could have traveled as far to Jamie's favourite Europa.

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