Indholdsfortegnelse for July 2020 i BBC Sky at Night

Later this month stargazers are in for a treat, when two giants of the night sky, Saturn and Jupiter, both reach opposition within a week of each other. Around this time they’ll be close together, and at their highest and brightest in the sky. We’ve got all the essential details you need to make the most of this wonderful summer evening view in the Sky Guide from page 39; it’s a foretaste of December’s Great Conjunction, when these two gas giant planets will appear as one bright star to the naked eye. Train a telescope on these worlds and you’ll reveal even more wonders: Saturn its majestic rings, and Jupiter its retinue of moons. Jenny Winder’s article on page 64 will really enrich your observations of the former, while Will…

The Universe’s oldest doughnut – otherwise known as a ring galaxy – has recently been spotted 11 billion lightyears away. It’s the first time such a ring has been spotted in the early Universe. “It is making stars at a rate 50 times greater than the Milky Way,” says Dr Tiantian Yuan from Australia’s ARC Centre for Excellence, who led the study. “Most of that activity is taking place on its ring – it truly is a ring of fire.” The ring is thought to have been formed by a collision of two galaxies. For this to be the case, one of the galaxies must have formed its thin disc – the plane which holds most of a spiral’s stars – much earlier than expected. “[With] this ring galaxy, we…

“Trying to understand the behaviour of systems hundreds of millions of lightyears away requires some ingenuity” Galaxies are funny beasts. They should be simple systems, and yet answering even basic questions about their formation ties astronomers in knots. Sure, their scale is breathtaking – the Milky Way’s few hundred million stars are nothing to be sniffed at – but the shapes of galaxies, and the patterns of the star formation that takes place within them, are sculpted almost entirely by gravity. We understand gravity and yet generations of astronomers have struggled to explain what we see. Part of the problem, of course, is the distance of the galaxies we’re trying to study. Trying to understand the behaviour of systems hundreds of millions of lightyears away requires some ingenuity and this…

This month The Sky at Night team look at the lives of stars. Chris investigates why Betelgeuse dimmed in late 2019 and speaks to researchers who’ve been photographing the star using the Very Large Telescope. Maggie wonders what the discovery of the brightest ever supernova means for our understanding of stars, while Lucie looks closer to home and reveals the science of our own Sun. Pete tries his luck at imaging a new supernova in galaxy M61. Four, 12 July , 10pm (first repeat Four, 16 July , 7.30pm) Check www.bbc.co.uk/skyatnight for more up-to-date information…

Our equipment specialist cures your optical ailments and technical maladies With Steve Richards Email your queries to scopedoctor@skyatnightmagazine.com I image with a Sky-Watcher 200PDS Newtonian reflector, but my images suffer from a bloom effect. I’ve recollimated and painted the inside of the tube black to no avail. What else can I try? DEREK MORTON The bloom effect is a haziness around bright light sources like stars and there are a couple of potential sources. The first is that the primary mirror may have a turned down edge, where the outer edge of the mirror is incorrectly polished. Sky-Watcher mirrors are pretty good in this regard, so this is the least likely cause. The second and more likely cause is that the mirror clips that hold the primary mirror in place…

Stamping through space Have you ever considered branching out to a new hobby? Philately has much more in common with astronomy than you may have realised What do you do on a cloudy night when it is impossible to get outside to observe the night sky? Perhaps you read a book or dig out the astrophotographs that you took a few weeks ago but never got around to editing? I like to focus my attention on my greatest and most rewarding hobby: philately. Even on a cold, wet December evening, with the prospect of weeks of cloud ahead, I can gaze upon the wonders of the Universe from the comfort of my sofa. Philately, or stamp collecting as it is more commonly known, may be something that you associate with…

As scientists consider sending missions to Jupiter in the coming years, one question that remains about the Galilean moons, Io included, is how did they form? The prevailing theory suggests it could have been a relatively rapid process; the moons combined from kilometre-sized objects encircling Jupiter in as little as a hundred thousand to a million years. Now, though, new research by Dr Yuhito Shibaike, at the University of Bern, and colleagues argues the process may have been much slower – perhaps taking something like 10 million years. In this new theory the chunks gathering together would have been smaller too, measuring only centimetres across. Among the evidence for the new theory is the fact that Europa actually possesses relatively little water, suggests Shibaike. “In our scenario, Europa got water…

Aristarchus Plateau Type: Lunar plateau Size: 250km Longitude/latitude: 52.4˚ W, 25.8˚ N Age: 3.8 billion years Best time to see: Five days after first quarter (1–3 & 31 July) and three days after last quarter (16–17 July) Minimum equipment: 50mm refractor Aristarchus is a bright, 40km diameter crater best seen near to the fuller phases of the Moon. It sits in the Oceanus Procellarum, in a feature-rich environment isolated within Procellarum’s lava. Aristarchus’s brightness is dramatic and can cause issues when attempting to image the inner parts of the crater: it’s tricky to maintain a good exposure level on surrounding areas without over-exposing its interior. Aristarchus’s brightness is due to its youthful age. Estimated to be less than 1.1 billion years old, the ejecta material hasn’t had time to be…

We all know that accidents can happen, but 2020 will be remembered as a year of catastrophe. The upshot is we have to pay greater attention to all kinds of near misses, including those from space in the shape of incoming asteroids, and on 30 June we do just that as the world marks Asteroid Day. Similarly, 2022 should also be a year to remember but in a quite different way. That October, humankind will test out responding to the asteroid threat by slamming a desk-sized NASA spacecraft called DART, the Double Asteroid Redirection Test, into the moonlet of a near-Earth asteroid at 6.6km per second. That historic event will mark our species’ next giant leap following the Moon landing – the first time we change the orbit of a…

For the last two years, the Transiting Exoplanet Survey Satellite (TESS) has been watching the stars, searching for new worlds. This month it completes its primary mission, having scanned 70 per cent of the sky – an area 400 times larger than that covered by its predecessor, the Kepler space telescope; but its job is far from done. As TESS moves into a two-year extension, we take a look over what the mission has already achieved and what it still could. Like Kepler, TESS has been tracking some 200,000 stars, watching out for the tell-tale dip in brightness as a planet passes – or transits – in front of the star. “TESS’s particular niche is that it’s sensitive to red dwarf stars,” says Sara Seager, deputy science director for TESS.…

• Price £2,599 (+ £59 shipping) • Optics 114mm (4.5-inch) reflector • Focal length 450mm, f/4 • Sensor Sony Exmor IMX224 • Mount Motorised single arm, altaz, Go-To • Power In-built lithium-ion rechargeable (9-hour) battery • Tripod Aluminium, adjustable height • Ports USB-C (for power) and USB-A for charging smartphone • App control Unistellar app for smart phones • Weight 9kg • Supplier Unistellar SAS • Email contact@ unistellar optics.com • https:// unistellar optics.com…

Why is Mars such a promising place to look for life? Around the time life was getting started here, Mars was also warm and wet, at least episodically, with streams and lakes and perhaps a deep northern ocean. There was a thicker atmosphere, a protective magnetic field and abundant sources of energy. It also had all the right chemical elements and organic building blocks for life. But what excites me most is the idea of a separate genesis on Mars – we could find a kind of life that’s totally unlike life as we know it here on Earth. Are we close to humans going to Mars? The leap from never having been to space in 1957, when Sputnik launched, to landing on the Moon in 1969 seems to be…

Will Gater Astronomy journalist “This was a fascinating story to write. Io’s dynamism is just amazing and the possibility we might see a mission to study it in the coming years is really exciting. Will takes an in depth look at Io, Jupiter’s moon. page 26 Pete Lawrence Sky at Night presenter “Mars fever is starting to take hold as the planet improves in both position and appearance ahead of a very favourable opposition in October”. Pete provides top tips for observing the Red Planet. page 32 Mary McIntyre Outreach astronomer “This was a really fun project. It’s amazing what you can make with very basic ingredients and I learned so much about Eros.” Mary enjoys making a realistic model of a near-Earth asteroid. page 66…

When I spoke to Thomas Rivinius I was fascinated by the accidental nature of the discovery. The team didn’t set out to find a black hole, but were interested in the properties of this unusual system. One of the two ‘normal’ stars spins quickly, the other slowly, an odd combination for a stellar system where they must have evolved together. Although ESO’s discovery had made headlines, Thomas explained with regret that they still hadn’t answered their original question. The black hole adds a further mystery – such objects are supposed to form in supernovae; how can a system bound by gravity survive such an event without being ripped apart? HR6819 will keep us guessing. Chris Lintott co-presents The Sky at Night…

Asteroid with a tail found An asteroid with a comet-like tail has been spotted near the orbit of Jupiter by the ATLAS Telescope. It’s thought the space rock contains water ice, which was recently disturbed to produce the tail. It is one of a growing number of crossover objects, bridging the gap between asteroids and comets. Telescope renamed after NASA pioneer Infrared telescope WFIRST has been renamed in honour of Nancy Grace Roman, NASA’s first chief astronomer, who died in 2018. Known as the ‘mother’ of the Hubble Space Telescope, Roman spent much of her career advocating for new tools to allow astronomers to explore the Universe. Nearest exoplanet confirmed The presence of a planet around our nearest star, Proxima b, has been independently verified by the European Southern Observatory’s…

Supernova snap Even in these trying times astronomy is still a great spirit lifter. I have been a regular attendee of Chesterfield Astronomical Society for the past 10 years but, of course, the current lockdown restrictions prevent us going to the Observatory. The fact that you can still enjoy astronomy from a back garden anywhere is a real bonus. I have my own telescopes but even if you haven’t you can still enjoy the beauty of the night sky. Anyone can take a deckchair outside or even a blanket and just look up; I often still just go out and look up at the night sky. If you do have a telescope or even binoculars, it opens up the sky to some fascinating objects. After the news of a supernova…

ONLINE TALKS The Search for Dark Matter A quick TED Talk in which astrophysicist Risa Wechsler explores how dark matter is key to the Universe’s origins. bit.ly/RisaWechsler Space junk Alice Gorman journeys through the abandoned probes, crashed orbiters, discarded rovers and other debris left out in space thanks to human exploration. www.youtube.com/ watch?v=T9NfLol6qEs Rescuing Hubble Former Shuttle astronaut Kathryn Sullivan, part of the mission to launch the famous Hubble Space Telescope, shares her experiences of a career in zero gravity. bit.ly/Hubblerescue DOCUMENTARIES Story of Jodrell Bank Discover how Bernard Lovell’s telescope put Britain at the vanguard of radio astronomy. www.bbc.co.uk/programmes/ b06pm5vf APPS Moon Phase Calendar A handy free app for the Moon’s location, phases, illumination, and rise and set times, plus useful information on the Sun too. Available for Android…

The night sky in the first half of 2020 was dominated by brilliant Venus in evening twilight. With Venus now in the morning sky, the low southern planets Jupiter and Saturn have taken up the reins in the evening sky. Later this year, however, there’s a big planetary event to look out for as the Red Planet appears high and bright in evening skies. Indeed, this autumn we’ll see the best opposition of Mars for many years to come. A planet is said to be in opposition when the Earth lies directly between it and the Sun. As the planet sits in the opposite part of the sky to the Sun, it’s positioned closest to Earth for its current ‘apparition’, or period of visibility. It’s a good time to observe…

Jupiter has a total of 79 officially recognised moons. Only four can be seen using a telescope as they perform their orbital dance around Jupiter. If you have a scope, point it at Jupiter and using a low to medium power eyepiece, get your young observers to sketch what they see. Mark the positions of the Moons as dots either side of the planet. Sometimes a moon may be behind (occulted) or in front of (transiting) Jupiter and won’t be visible. Use our graphic on page 45 to help identify them. Remember, your scope may show a view which is upside down, ie, with south up. www.bbc.co.uk/cbeebies/shows/stargazing…

Apollo 8 astronaut Rusty Schweickart is one of the founders of the B612 Foundation, a sponsor of Asteroid Day, who has spent years investigating asteroid deflection techniques. He explains: “More and more asteroids were being discovered, but nobody was talking about what to do if one comes our way. We asked if technology was at a point where it’s worth considering what to do. It turned out it was: with sufficiently advance knowledge we probably could deflect an asteroid.” That work led in turn to the first inklings of AIDA, and what has become DART and Hera. “We stopped talking about a deflection mission and switched to a deflection campaign,” says Schweickart. “You need an observer spacecraft as well as a deflector, to be sure the deflection has worked as…

Asteroids are small, rocky bodies, most of which orbit the Sun in the asteroid belt between Mars and Jupiter. These space rocks are leftover material from the formation of the Solar System, and although ground-based observations of asteroids can be a little underwhelming due to their low surface brightness, studying them is important for our understanding of planetary formation. Making an asteroid model allows you to study its morphology in three dimensions and is a fun activity; combining astronomy with crafts is a great way to engage the whole family, especially children. You can make the model using salt dough, which requires only three ingredients and you probably already have these in your store cupboard. At the time of writing, certain kinds of flour may be more difficult to find…

Whether you’re a seasoned astro- photographer or a beginner, we’d love to see your images. Email them to contactus@skyatnightmagazine. com. Ts&Cs: www.immediate.co.uk/ terms-and-conditions We’ve teamed up with Modern Astronomy to offer the winner of next month’s Gallery a finder–guider adaptor, which connects T-thread guide cameras from ZWO, Orion and others to 9 x 50 standard finders from Sky-Watcher. The accessory comes with full instructions and support. www.modernastronomy.com • 020 8763 9953…

1 Baader MaxBright II binoviewer 1.25-inch Price £390 • Supplier Harrison Telescopes www. harrisontelescopes.co.uk Make the switch to stereo vision with this binoviewer, which splits the light to let you look through your scope with both eyes. The non-slip finish and ergonomically designed knobs are specifically designed for easy use after dark. Eyepieces not included. 2 RS Pro silia gel dessicator, 50g Price £14.42 • Supplier RS https:// uk.rs-online.com Damp can ruin a telescope, so use this silica gel desiccator to keep your storage space free of moisture. When the blue indicator turns pink, reactivate the gel by cooking it in the oven. 3 Personalised celestial print scarf Price £18 • Supplier Not On The High Street www. notonthehighstreet.com This beautiful scarf is decorated with gold stars…

When to use this chart 1 July at 24:00 AEDT (13:00 UT) 15 July at 23:00 AEDT (12:00 UT) 31 July at 22:00 AEDT (11:00 UT) The chart accurately matches the sky on the dates and times shown for Sydney, Australia. The sky is different at other times as the stars crossing it set four minutes earlier each night. JULY HIGHLIGHTS Comet 2P/Encke is famous for being a comet with one of the shortest periods, only 3.3 years. Since passing through perihelion in late June, ‘Encke’ has moved into the evening sky. The comet opens July in Cancer at its maximum brightness (possibly 7th magnitude), setting around the end of astronomical twilight. As it moves away from the Sun it gains altitude, passing through Hydra, Sextans and Crater before closing…

July 1965 On 23 July 1965, The Sky at Night celebrated its 100th episode. The team tackled one of humanity’s greatest questions: are we alone in the Universe; and if there are civilisations on other planets, how would we contact them? Though astronomers and philosophers alike had pondered the question for decades, technology only caught up to their musings in the 1960s. Astronomers were then able to listen out for alien radio signals leaking out into space. In 1960, US astronomer Frank Drake began Project Ozma, using the Green Bank radio telescope in West Virginia to listen to nearby stars. used wide-field antennae to search large sections of the sky, hoping to hear a powerful radio signal among the noise. Since the 1960s there have been many large-scale searches for…

Tony Moss When our local astronomy club can meet up again. Laurence Blundell The oppositions of Jupiter, Saturn and Mars, and also (hopefully!) visiting some astronomy shows, some of which had to be postponed earlier in the year. Gary Hendrick Great Conjunction of Jupiter/Saturn on 21st Dec. Keith Moseley Any decent comet that doesn’t disintegrate or hide in the Southern Hemisphere.....or just some noctilucent clouds will do. David Millar Galloway Star Camp in October. Ben Head Last night I saw four meteors in the space of 90 mins; three were dim but one was really bright. I can’t wait for the Perseids this year – I’ve found the perfect location to watch. AR Gavin The launch of the NASA Mars 2020 mission. Barry Gowans Honestly, I’m looking forward to the…

ESOCast Enjoy bite-sized videos from the European Southern Observatory The European Southern Observatory (ESO) builds and operates some of the most advanced telescopes in the world, including the Very Large Telescope and ALMA, whose stunning images we often feature in our Eye on the Sky pages. Now you can keep up with revelations from astronomers at ESO via ESOcasts, bite-sized videos with the latest science and news from their observatories in northern Chile. Films include a spectacular zoom into Betelgeuse, recently revealed to be undergoing unprecedented dimming, a film about the odd orbit of a star around the black hole Sagittarius A*, and a look at extraordinary exoplanets. And, of course, there are enviable shots of the Milky Way above the Chilean desert. As well as superb visuals – some…

Universal time (UT) and British Summer Time (BST) Universal Time (UT) is the standard time used by astronomers around the world. British Summer Time (BST) is one hour ahead of UT RA (Right ascension) and dec. (declination) These coordinates are the night sky’s equivalent of longitude and latitude, describing where an object is on the celestial ‘globe’ Family friendly Objects marked with this icon are perfect for showing to children Naked eye Allow 20 minutes for your eyes to become dark-adapted Photo opp Use a CCD, planetary camera or standard DSLR Binoculars 10x50 recommended Small/ medium scope Reflector/SCT under 6 inches, refractor under 4 inches Large scope Reflector/SCT over 6 inches, refractor over 4 inches GETTING STARTED IN ASTRONOMY If you’re new to astronomy, you’ll find two essential reads on…

Collisions have been a driver of Solar System history, and humans have added to their number. Apollo lunar modules and Saturn V third stages were collided with the Moon to trigger artificial ‘moonquakes’, which revealed valuable information about the Moon’s interior structure. In 2005 NASA’s Deep Impact collided with the comet Tempel 1 to uncover subsurface material. The large dust plume meant the crater couldn’t be imaged at the time and a 2011 flyby by the Stardust mission sent back unimpressive results. More dramatic was NASA’s 2009 LCROSS mission, which slammed a Centaur upper stage at 2.5 km/s into Cabeus crater near the Moon’s south pole. A ‘shepherd’ spacecraft flew through the impact plume, sniffing out water ice and carbon dioxide – of potential use to future colonists. Last year,…

TOI 700d TESS’s first Earth-sized world found within the habitable zone. Its orbit is only 37 days long, meaning it’s much closer to its star, however the star is a red dwarf and so much cooler than the Sun. TOI 270 system The planetary system TOI 270 has two mini-Neptunes. Planetary scientists will compare them to see how they differ, given both planets formed in the same environment. Pi Mensae c The first new planet that TESS discovered back in 2018. It’s around twice the size and five times the mass of Earth, and orbits a Sun-like star once every six days. TOI 1338 A circumbinary planet, TOI 1338 orbits around a tight binary pair of stars. The planet candidate was initially dismissed, before being spotted by Wolf Cukier, a…

When will this all be over? We’ve all been asking the question during COVID-19, but it has also been on the minds of solar astrophotographers for an entirely different reason. Our Sun entered the depths of solar minimum back in 2018 and we are wondering when it will wake up. What can a solar photographer do when the Sun constantly shows a blank face? Our answer is to look at the Sun’s edge, while remembering to stay safe – never look at the Sun directly and always use solar filters on any equipment that is pointed towards it. Even on days when the disc is spotless, the limb often sports handsome prominences. These arcs of hydrogen plasma are photo-worthy subjects for any astronomer equipped with a hydrogen-alpha (Ha) filter. Using…

We have reviewed many small telescopes in Sky at Night Magazine and have often added the proviso that you have to keep visual expectations low. Unfortunately, small scopes don’t have a great deal of light grasp and will not produce detailed images like those often found on their nicely designed boxes. The Unistellar eVscope challenges that view, while perhaps giving an insight into the future of visual astronomy. The telescope was developed as a user-friendly system – by Unistellar in association with the SETI Institute – to be used for citizen science projects, so we were eager to check it out. Essentially, the eVscope marries a Sony IMX224 sensor with a 4.5-inch, f/4 reflector and an electronic eyepiece, alongside cutting-edge electronics and computing. The telescope tube sits on a single-arm…

The Sirens of Mars Sarah Stewart Johnson Allen Lane £20 • HB Surely there is life on Mars – or at least that is what was thought by astronomers from the late 1600s all the way up to the 1980s. But in recent years that statement has taken on a whole new meaning. This book takes us on a voyage through our relationship with the Red Planet and makes us appreciate the tremendous journey it has made in the popular zeitgeist, from a world covered in carefully engineered canals for advanced alien inhabitants, to a lush vegetated haven and finally to the cold, ancient and desolate wasteland we know today. Looking behind the scenes of life as a modern planetary scientist, The Sirens of Mars follows the author’s experiences of…