Innholdsfortegnelse for No. 158 i All About Space

ISSUE 158 From Carolyn Porco, a planetary scientist who studies the outer Solar System, to Henrietta Swan Leavitt, an astronomer who worked out how to measure the vast distances to galaxies with the help of Cepheid variables, this issue we celebrate some of the astounding women who changed our understanding of the universe. Elsewhere in the issue, we uncover whether the dinosaurs were wiped out by the Sun’s twin and why the swift planet Mercury seems to be shrinking, while physicist and science communicator Michio Kaku gives us a quick guide on the complex universe. There’s plenty to get stuck into this month. And that’s not all – we have your favourites here once again, including this month’s stargazing guide, offering you a fantastic mix of night-sky targets visible to…

The black hearts of galaxies have had their history told almost in full for the first time as astronomers combined X-ray observations with detailed supercomputer models to chronicle the growth of supermassive black holes over 12 billion years of cosmic history. The scientists have shown that the black hole at the core of our Milky Way attained its 4 million solar masses relatively late in its history. Supermassive black holes range from millions of times more massive than our Sun to billions of times more massive, but their origins are unclear, and how they grew to such enormous masses has been a challenge for astronomers to understand. Now, Fan Zou and Niel Brandt, both of Penn State University, have led a team that connected the two mechanisms of black-hole growth…

NASA’s Mars Sample Return program has hit several snags in recent months after being told its current $11 billion (£8.64 billion) plan is too expensive. The existing Mars Sample Return (MSR) mission plan would require multiple launches to Mars in order to eventually place a Mars Ascent Vehicle (MAV) on the Red Planet’s surface. From there, either the Perseverance rover or other small retrieval helicopters – similar to NASA’s Ingenuity rotorcraft – would pick up Mars samples that Perseverance has already collected and load them into the MAV. Then an ascender would launch the samples up to orbit, where a spacecraft would collect them and haul them back toward Earth. Sounds costly and overly ambitious? NASA thinks so, too. That’s why the agency has selected ten studies submitted by industry…

Mercury can be easy to overlook. As the closest planet to the Sun, it’s hard to spot on its fleeting visits to our skies. Over the past few decades, however, our view of the innermost planet has been transformed by NASA’s MESSENGER space probe. The first spacecraft to orbit Mercury revealed that this mysterious world has a complex history of its own, with a distant volcanic past, a core much larger than that of any other planet relative to its size and an active magnetic field. But perhaps most intriguing of all is the evidence that this tiny planet has shrunk considerably since it formed. “Mercury is the least understood of our Solar System’s four terrestrial worlds because until relatively recently it was extremely hard to image or visit,” says…

About 66 million years ago, an asteroid slammed into Earth, wiping out more than 75 per cent of all life on our planet – including the dinosaurs. What caused that asteroid to come our way has perplexed scientists for a long time. Was it just a coincidence, or were bigger powers at play? Back in 1984, a group of astronomers suggested the latter with a pretty controversial paper: Marc Davis, Piet Hut and Richard Muller proposed that every 26 to 30 million years, a companion star to our Sun would swing past the Solar System, potentially disrupting a family of asteroids and comets at our Solar System’s edge – those in the Kuiper Belt and Oort Cloud – and sending some our way. They dubbed this star Nemesis, after the…

Fast radio bursts (FRBs) are intense, short-lived blasts of radio waves hailing from beyond the Milky Way that can emit the same amount of energy in just thousandths of a second that the Sun takes three days to emit. However, despite their power and the fact that around 10,000 FRBs could erupt in the sky over Earth every day, these blasts of radio waves remain mysterious. One of the biggest puzzles surrounding FRBs is why most flash once and then disappear, while a tiny minority repeat the flash. This has led scientists on a quest to discover the mechanisms that launch FRBs. Some even believe different celestial objects can produce both repeating and non-repeating FRBs. Scientists from the University of Toronto used the Canadian Hydrogen Intensity Mapping Experiment (CHIME) to…

On New Year’s Day 2019, NASA’s New Horizons spacecraft radioed to Earth images of the farthest object ever explored: a snowman-shaped primordial object named Arrokoth, one of many frigid residents in the Kuiper Belt that sits beyond Neptune’s orbit. The pictures revealed the surface of the two-lobed 34-kilometre (21-mile) wide structure to be rusty red, and this mysterious hue has kept scientists puzzled ever since. Originally, scientists proposed that radiation from the solar wind and galactic cosmic rays, which routinely bombard Arrokoth’s surface, somehow converts primitive ices like methanol into organic molecules that give off an ultra-red hue. Details about how this process would work, however, remained unclear. Now we may have some answers. A lab experiment that mimicked space radiation exposure similar to the kind Arrokoth’s surface experiences found…

1 Messier 39 Just north of the North America Nebula, Messier 39 is just visible to the naked eye and makes a superb target through decent binoculars. 2 Messier 15 Just on the edge of naked-eye visibility, this globular star cluster looks like a fuzzy ball of light in 10x50 binoculars. 3 North America Nebula (NGC 7000) Lying just to the east of the bright star Deneb, this large region of ionised gas is faintly visible with binoculars from a dark-sky site. 4 Fomalhaut This is a bright star of the Southern Hemisphere that is visible in much of the north, but only for a short time. 5 Messier 2 Similar to Messier 15, this globular cluster is just at the limit of naked-eye visibility. It contains some of the oldest stars…

Von Braun was born on 23 March 1912 in the town of Wyrzysk in Poland. His mother gave him a telescope at a young age, which inspired his passion for astronomy, while his love of rocketry was apparent from the age of 12 when he accidentally blew up a firework-powered toy car in a crowded street. Von Braun and his family moved to Germany following World War I, and it was at school in Weimar, and later on the island of Spiekeroog, that von Braun took up physics and mathematics to learn more about rocket engineering. In 1932 he graduated from the Berlin Institute of Technology with a degree in aeronautical engineering, and two years later he had a PhD in physics from Frederick William University, now the Humboldt University…

29 May 2024 Webb finds a dusty skeleton in a starburst galaxy’s closet The dwarf galaxy NGC 4449 is the star of the show in the James Webb Space Telescope’s latest cosmic portrait. Located 12.5 million light years away in the constellation of Canes Venatici, the Hunting Dogs, NGC 4449 has much in common with our very own Large Magellanic Cloud (LMC), the satellite galaxy orbiting the Milky Way. Both are small and irregular in shape, and each has a distinctive bar running through its centre. However, whereas the LMC has one extreme region of star formation, which is the 30 Doradus region famously known as the Tarantula Nebula, NGC 4449 has enhanced star-forming rates across its length and breadth. Indeed, there’s so much star formation going on that NGC…

One day, we’ll bring samples home from Mars – but until then we have some Martian material to work with, thanks to meteorites from Mars that crashed into Earth. Scientists with the Scripps Institution of Oceanography are studying these, gaining insight into the early formation of the Red Planet. They’ve gleaned information about the structure of Mars’ crust and mantle. The meteorites indicate Mars has an atmospherically altered upper crust, as well as a complex deeper crust. They suggest it has a mantle from which plumes emerge through the crust to produce a specific type of volcano, and have also indicated that Mars has reservoirs throughout its internal structure. “Martian meteorites enable us to make precise and accurate measurements and then quantify processes that occurred within Mars and close to…

Come 2029, skywatchers can glimpse at least one ‘star’ in the sky made by humans. NASA announced plans to place a small satellite in Earth orbit at a little over 35,400 kilometres (22,000 miles) above our planet’s surface – far enough for the satellite to mimic a real star to telescopes on Earth. Scientists say the satellite, named Landolt, wouldn’t be bright enough to be seen with the unaided eye, but if you happen to have a personal telescope at home, you may be able to spot a shoebox-sized object hovering above the United States in a stationary position. The mission’s primary goal is to help calibrate telescopes on Earth and create new, more accurate catalogues of the brightnesses of real stars. Once in orbit, the satellite will beam eight…

While the Martian rovers Spirit, Opportunity, Curiosity and Perseverance have explored further afield than ever before, the process is frustratingly slow. Curiosity’s top speed is only 200 metres per day, partly due to the difficulty of controlling a robot with a 20-minute round trip communications delay, limiting the reach of exploration. Numerous proposals have been put forward for various bodies in the Solar System using flying probes of various kinds. Free-flying balloons, dirigible airships, gliders and even hopping probes that jump across terrain have all been proposed, but NASA’s latest airship study is unique – it will fly on a vacuum lift. Balloons and airships float in an atmosphere by displacing some of the atmosphere with something lighter, just like the way boats float by displacing water for air –…

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1 Solidifying inner core Mercury’s core is richer in iron than those of other terrestrial planets. The innermost core may have frozen into a solid ball of iron, with some other heavy elements present. 2 Swirling outer core As Mercury’s outer core of molten iron churns and swirls, it carries electrical currents that generate a magnetic field around the planet, which has about one per cent the strength of Earth’s. 3 Iron sulphide layer MESSENGER showed that Mercury’s mantle is surprisingly dense. In 2012, NASA scientists proposed that the lower mantle is composed of dense iron sulphide that has risen out of the core and solidified. 4 Upper silicate mantle The upper part of Mercury’s mantle is composed of silicate rocks with very little iron. Such a thin layer contains…

1 Molecular clouds Stars are created when concentrations of interstellar dust and gas, known as molecular clouds, collapse under their own gravity. 2 Stellar pairs It’s now thought that almost all stars in the universe form in pairs from the same molecular cloud, as observed in starforming regions. 3 Cloud core The core of the molecular cloud can have a mass up to 10,000 times that of our Sun. This is the part of the cloud that collapses first. 4 Protostars The core collapses, forming multiple protostars. They take shape from clumps of matter that have up to 50 times the mass of our Sun. 5 Heating up As gas falls onto the protostar, it begins to heat up. This rapidly increases its size until it stops accreting gas and becomes…

Professor Stephen Kane was intrigued and excited. As he looked at the data, made sure his calculations were correct and reality began to quickly set in, he sat back in his chair, a look of astonishment stretching across his face. In the course of studying a star system known to harbour a giant planet, he’d come across an object which was unlike anything he had seen before. And the discovery has the potential to be rather explosive. The object is some 66 light years from Earth in a star system called HD 104067 in the southern constellation of Corvus. It has long been known to contain a star with 82 per cent of the mass and 77 per cent of the radius of the Sun, and it’s said to be…

PLANET OF THE MONTH Although it will be much more impressive later in the year, Mars is our planet of the month because of all the planets currently on view, it has the most interesting month ahead. Not only will it be bright enough to be seen easily with the naked eye, but it will have fascinating celestial close encounters with the Moon and other planets and will be steadily increasing in brightness as the days and nights pass. At the start of our observing period Mars will be a morning star, rising in the northeast around three hours before the Sun. It will be found close to the Pleiades star cluster in Taurus, and will have two other planets nearby, too. Brighter, silvery-blue Jupiter will be shining to its…

Scientists believe Earth may have briefly lost protection from the Sun around 2 million years ago, left to endure the extreme environment of interstellar space as the Solar System passed through a dense cloud of gas and dust between stars. At that time, early human ancestors shared our planet with prehistoric animals like mastodons and sabre-toothed tigers. It’s also when Earth was in the midst of the ice age that ended only around 12,000 years ago. Ice ages are brought about by a range of factors, including our planet’s tilt and rotation, carbon dioxide levels in its atmosphere and shifting plate tectonics and volcanic eruptions at its surface. However, given the timing of when scientists think Earth plunged through interstellar space, this research suggests radical changes in our planet’s climate…

In the depths of our Solar System, scientists have reported the possible existence of a molecule known as aquodiium – an elusive cousin of the ammonium ion. If true, that could explain oddities in Neptune and Uranus’ magnetic fields. This is a big deal because stable aquodiium, which consists of four atoms of hydrogen and one atom of oxygen (H4 O2+) , has never been observed before due to the high-energy barrier involved in adding a second proton to the molecule hydronium (H3 O+), which is how aquodiium must be formed. Hydronium, however, is a bit easier to create. It forms through the fundamental process of adding a proton to water. The jump from hydronium to aquodiium is the hard part. However, with the help of advanced computer models, researchers…

Contraction comes to an end In a billion or more years from now, the shrinking of the interior finally dwindles to a point where it cannot create enough stress for more faults to form in the crust. More faulting on the surface Small-scale faults may continue to form and even grow in size as the continued cooling and contraction of Mercury’s interior places more stress on the crust. Fresher faults are wiped away Over hundreds of millions of years, small-scale faults are erased from the surface, obscured by meteorite bombardment. The core continues to solidify As the interior continues to cool, the solid inner core of iron grows in size, leaving the molten iron outer core trapped between two solid shells. The magnetic field shuts down The dynamo effect of…

Astrange planet discovered with NASA’s Transiting Exoplanet Survey Satellite (TESS) has astronomers confused. Despite getting relentlessly bombarded with radiation from its red giant parent star, the world has hung on to its atmosphere against all odds. It is also smaller, older and hotter than scientists thought possible for such a planet. In truth, the exoplanet should be a bare husk of rock due to its proximity to the star TIC 365102760, located around 1,800 light years away from Earth. Yet the world, nicknamed ‘Phoenix’, has emerged from the flames of its host star with a nice and puffy atmosphere. Phoenix, or TIC 365102760 b as the planet is officially designated, is part of a rare class of planets called hot Neptunes. These are worlds with radii smaller than Jupiter’s, but…

1 How big was the asteroid? The dinosaur impactor is thought to have been about 10 to 15 kilometres (six to nine miles) in diameter, enough to cause a lot of damage. 2 Where the asteroid hit Earth The crater from the asteroid that killed the dinosaurs is located near the town of Chicxulub in Mexico, which the asteroid is named after. 3 When did the asteroid impact? The Chicxulub asteroid is thought to have hit Earth about 66 million years ago, wiping out 75 per cent of all life on Earth. 4 How big is the crater? The resultant crater from the impact measures more than 180 kilometres (110 miles) across and is 20 kilometres (12 miles) deep. 5 Where Nemesis would be now If it exists, Nemesis would now be at its furthest point,…

Many think the summer sky is too bright to allow observation of faint and fuzzy deep-sky objects, but if you stay up late the sky is just dark enough to let you see some lovely sights. After midnight – providing the sky isn’t lit up with a display of bright blue and silver noctilucent clouds or the glowing full Moon – a telescope will give you very pleasing views of some of astronomy’s most famous objects. Although the broad, frothy band of the Milky Way dominates the sky, running right through the centre of Cygnus (the Swan), or the Northern Cross, cutting it and the whole sky in half, embedded in it are subtly coloured nebulae – regions where stars are being born. Elsewhere you can see the ghostly remains…

Space Shuttle Discovery Cost: £169.99 /$199.99 From: LEGO 1 If you’re a space fan, there’s no denying that this LEGO NASA Space Shuttle Discovery is one of the best LEGO space sets you can get your hands on right now. It’s an authentic recreation of NASA’s real Discovery shuttle, featuring realistic elements such as an opening payload bay, retractable landing gear and five seats for the crew. Unfortunately, you’ll have to use your imagination there since this set doesn’t come with Minifigures, but it’s a small price to pay for something that’s otherwise so detailed. As an added bonus, it also includes a model of the Hubble Space Telescope, which can be handily stowed away inside the payload bay. Rocket Launch Centre Cost: £129.99 /$169.99 From: LEGO 2 This set…