Innehållsförteckning för September 2023 från BBC Sky at Night

Later this month, OSIRIS-REx will return to Earth and complete the final stage of its seven-year-long mission by sending a small circular capsule down from orbit to land in the deserts of Utah. Inside is an important payload: pristine sample material collected from its target in deep space, asteroid Bennu. In our feature on page 66, features editor Ezzy Pearson looks at what will happen to these samples from another world once they're back on Earth and the secrets that planetary scientists expect the space rocks to reveal about the early Solar System. If the OSIRIS-REx capsule's fiery descent through Earth's atmosphere was to happen at night and in a less remote location, it may well have made it into our feature on page 34 too. Here, astronomer and writer…

Katrin Raynor Astronomy writer “Darker skies are on their way and there's a lot to look forward to, including a comet, a partial lunar eclipse and the return of every stargazer's favourite, Orion”. Discover autumn's unmissable sights on page 28 Ezzy Pearson Features editor “OSIRIS-REx is the latest mission to bring back pieces of space rock, but it won't be the last. With missions heading to the Moon and Mars, it's an exciting time for sample returns!” Read all about the rock hunters on page 66 Steve Tonkin Binocular astronomer “Starhopping not only helps you navigate the night sky with ease, it also helps you learn how constellations relate to each other. You'll quickly build up a familiarity with the night sky.” Learn how to do it on page 72…

A year into what will hopefully be a 20-year mission, JWST has given us spectacular images of everything from Jupiter to the Orion Nebula. Yet the results that have attracted some of the most attention - images of what seem to be the most distant galaxies ever seen - are hardly spectacular. Though it's impressive that the light from each of these galaxies has been travelling towards us for more than 13 billion years, so that we see them as they were just as the Universe was getting started, the truth is that we see them as nothing more than faint blobs. So what can we really know about a galaxy when all we have is a blurry, blobby image? Obtaining spectra - where we measure out the intensity of…

MESSAGE OF THE MONTH This month's top prize: two Philip's titles (The ‘Message of the Month writer will receive a bundle of two top titles courtesy of astronomy publisher Philip's: Nigel Henbest's Stargazing 2023 and Robin Scagell's Guide to the Northern Constellations Winner's details will be passed on to Octopus Publishing to fulfil the prize Lunar love story Stuart Hawk's letter in your recent issue CLibration spotted!’, Interactive, July 2023), really struck a chord with me. It described lunar libration and how we see nearer 59 per cent of the Moon's face rather than 50 per cent because of its slightly tilted rotation axis and its slightly non-circular orbit around Earth. Back in 2012, I began photographing the full Moon every month here in North Wales. I still capture the…

Capturing the Visible Universe in a Single Image Astronomical Society of Edinburgh, online, 15 September, 7:30pm US astrophotographer and author Charlie Bracken and former BBC producer Max Whitby spent two years creating a single image that shows the entire celestial sphere in both RGB colour and hydrogenalpha. Find out how they did it in this free, livestreamea talk. www.youtube.com/@ AstronomicalSocietyof Edinburgh The Changing Climate of Mars St James the Less Church Hall, Maidenhead, 1 September, 7:30pm University of Oxford planetary physicist Peter Read will discuss changes in the Red Planet's atmosphere, weather and climate overthe millennia. Free for Maidenhead Astronomical Society members, non-members £2. www.maidenhead-astro.net Stellar Evolution Kindle Centre, Belmont Road, Hereford, 1 September, 7pm Former BAA president Roger Pickard visits Herefordshire Astronomical Society to discuss the birth, life and death…

As September approaches, astronomers leave the long, hazy days and short, bright nights of summer behind and welcome the return of dark skies. The longer, darker nights allow us to view some of the most loved and prized night-sky objects that return each autumn. And there's a lot to look forward to this season, whether you're using your naked eye, binoculars or a telescope. This guide will help you find some fascinating objects, either from your garden or from a dark-sky site away from light pollution, whether you're an absolute beginner or a more well-seasoned astronomer. Remember to wrap up warm and grab a red torch to follow this guide as you head out into the dark. Downloading a stargazing app will help you find your way around the targets…

1 Friday The Alpha Aurigid meteor shower reaches its peak today. The ‘equation of time’ – the difference between time reported by the artificial ‘mean Sun’ and the apparent Sun – equals zero, meaning sundial shadows report the correct time today! 4 Monday This evening has a 70%-lit waning gibbous Moon located 3.3° northeast of mag. –2.5 Jupiter. Catch the pair rising above the eastnortheast horizon from around 22:00 BST (21:00 UT). 5 Tuesday The waning gibbous Moon sits near Uranus and Jupiter (see page 46) occulting mag. +4.3 Botein (Delta (δ) Arietis) around 04:45 BST (03:45 UT). This evening the 60%-lit Moon sits near the Pleiades. 7 Thursday An opportunity to see the clair-obscur effect known as Gruithuisen's Lunar City occurs this evening, with optimum conditions around midnight BST (23:00 UT). See page…

DIY ASTRONOMY Practical astronomy projects for every level of expertise T his project takes a few simple materials and turns them into a stunning space scene, while providing numerous learning opportunities for the whole family. The diorama isn't intended to provide any kind of correct scale in terms of the sizes of the planets or the distances between them, although we still chose different-sized polystyrene balls to give an overall impression of their relative sizes. You can use any size of balls for your planets, but make sure that they'll all fit in your box. We hung our planets in the correct order, but at different heights and depths - be as creative as you like. In ours, Saturn is hanging at an angle, although this was purely to save space!…

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These new results will teach us a huge amount about supermassive black holes and the environments they live in near the centres of galaxies. Remarkably, we've also learnt a bit about the Solar System along the way. The signal the gravitational wave hunters are looking for is very sensitive to the movement of Earth – and our planet is pulled this way and that not only by the Sun, but also by the other planets. These new results depend particularly on tracking the orbit of Jupiter. Together with the pulsar work, the team measured the position of the Solar System's barycentre – the point around which we orbit – to a precision of 100 metres – a little more than the length of a football pitch. Astonishing. Chris Lintott co-presents…

July saw the successful launch of two major space missions: the European Space Agency's (ESA) Euclid and the Indian Space Research Organisation's (ISRO) Chandrayaan-3 mission to the Moon. Euclid launched on 1 July at 16:12 BST, heading towards L2, a gravitationally stable orbit around the Sun. The spacecraft will spend at least six years creating a map of the cosmos at large scales. Astronomers will use this data to investigate the ‘dark Universe’, exploring how the role of gravity, dark matter and dark energy have shaped the cosmos over time. Two weeks later, on 14 July, the Indian Chandrayaan-3 lunar mission launched at 10:05 BST, setting course for the Moon shortly afterwards. The mission is a follow-up to a previous landing attempt that failed in September 2019 following a software…

Andy Sawers Lots of fun and arguments can be had with this list! Fr Georges Lemaître belongs on it. And while Einstein was no astronomer, has anyone had a greater impact on how we understand the Universe? Lucas Borkowski It's great to see so many ladies on this list. Tim Hager Karl Jansky, Subrahmanyan Chandrasekhar, EE Barnard, Henry Draper. Mick Cassidy The 3rd Earl of Rosse. Niky Astrea The great Aristarchus! The first one to propose the heliocentric system. Kevin Nolan Percival Lowell might today be recognised as a pseudo-scientist! Even if you regard him as one, how does he trump Hoyle or the Third Earl of Rosse? Steve Plenty My dad, who got me into visual astronomy. I'm still going after 40 years - thank you dad.…

Herstmonceux Astronomy Festival The Observatory Science Centre, Herstmonceux, Hailsham, 1-3 September This annual festival returns to the site of the old Royal Observatory to welcome the start of a new season of longer nights. The weekend-long festival is aimed at seasoned astronomers and families alike. Expect astronomy talks, including a foodbased guide to cosmology with Professor Kathy Romer and an audience with The Sky at Night's Chris Lintott(both pictured above), observing through telescopes (weather permitting), planetarium shows, solar observing, historic telescope demos and a pub quiz! Weekend tickets are £54 per adult and £42 per child. Day tickets are £13.50 per adult and £10.50 per child, with discounts for family tickets available. For more details, visit www.the-observatory.org/events.…

The planets put on a captivating show throughout autumn, all easily viewed with the naked eye or optical aids. At points during each planet's orbit, Earth is positioned between them and the Sun. When this happens, the planet is said to be at opposition. There are also times during a planet's orbit where it may be obscured from view by another object in the sky. This is called an occultation. A lunar occultation occurs when the Moon obscures an object from view. Each planet's orbit varies. The inferior planets, Mercury and Venus, orbit very close to the Sun compared to the outer planets. This can make viewing Mercury especially tricky, but during periods of greatest elongation, when these planets are furthest from the Sun in their orbit, we get a…

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…

KEY TO STAR CHARTS When to use this chart 1 September at 01:00 BST 15 September at 00:00 BST 30 September at 23:00 BST On other dates, stars will be in slightly different positions because of Earth's orbital motion. Stars that cross the sky will set in the west four minutes earlier each night. How to use this chart 1. Hold the chart so the direction you're facing is at the bottom. 2. The lower half of the chart shows the sky ahead of you. 3. The centre of the chart is the point directly over your head. Sunrise/sunset in September* Moonrise in september* *Times correct for the centre of the UK Lunar phases in September MORE ONLINE Paul and Pete's night-sky highlights Southern Hemisphere sky guide…

1 NGC 7243 We'll start in Lacerta, a small, dim constellation with an asterism that looks like a tiny Cassiopeia, called the Mini W. Open cluster NGC 7243 sits 1.5° west of the middle star of the vertically arranged Mini W, mag. +4.5 4 Lacertae. The cluster is a fairly loose collection of blue and white stars occupying an area 21 arcminutes across. A 150mm scope shows around 40 stars. With a bit of imagination, a group of the brighter members form part of a semi-circle, reminiscent of Corona Borealis, the Northern Crown. This curve of stars shows around 25 members with a 250mm instrument, an impressive asterism in its own right. The cluster is around 2,800 lightyears distant and estimated to be 100 million years old. □ SEEN IT…

It's the premise of many sci-fi tales, but the threat of bringing back some alien microbe that could harm our planet is something all space agencies take very seriously. Billions of years of being bombarded with cosmic radiation have rendered asteroids safely sterile - but that's not the case on Mars. “Though we have seen no evidence for life on the Red Planet so far, it would be naive to assume there isn't any, given it's a planet with an atmosphere,” says Sara Russell. The Perseverance rover is currently collecting a series of samples on Mars, which NASA and ESA hope to return to Earth some time in the next decade. Already there are plans for what precautions are needed to keep Earth safe. “The first samples will be taken…

ASTROPHOTOGRAPHY CAPTURE Take the perfect astrophoto with our step-by-step guide Lunar imaging is generally one of the less demanding parts of astrophotography - the Moon is bright, with lots of contrasting features for accurate focus and its brilliance in the night sky makes it fairly easy to locate with a camera. However, not all Moon phases are alike, and one in particular will push your imaging skills to the limit: the thin Moon. A thin Moon is the very thin crescent phase you get just before and after new Moon. Visibility of such crescents depends on several aspects, including weather, timing and date. Let's take these in turn. Weather is fairly obvious because if it's cloudy the Moon will be hidden. However, as thin Moons lack the brilliance and contrast…

New astronomy and space titles reviewed Interstellar Avi Loeb John Murray £20 • HB The central argument of Interstellar is that humanity is unprepared for the realisation that advanced extraterrestrial civilisations are common, and that we have not even begun to explore that possibility to the full extent of our capabilities. Theoretical physicist Avi Loeb introduces us to the Galileo project whose aims are: to obtain high-resolution, multi-spectral images of Unidentified Aerial Phenomena (UAP); to design a launch-ready space mission that can intercept and image objects of known interstellar origin; and recover one of only two known meteorites of interstellar origin off the coast of Papua New Guinea. Although these aims are admirable, and possibly warranted, it is still a leap of faith to conclude that anything unexplained or anomalous…

Television Find out what The Sky at Night team have been exploring in recent and past episodes on page 18 Visit our website for competitions, astrophoto galleries, observing guides and more Social media Follow us on Twitter, Facebook and Instagram for space news, astro images and website updates Podcasts Discover the best things to see in the night sky every week by listening to our Star Diary podcast Tablet/phone Get each month's issue on your Apple or Android device, now with bonus image galleries eNewsletter The best targets to observe each week, delivered to your inbox. Visit bit.ly/skynewsletter Online Find out more at: www.skyatnightmagazine.com…

Sandwich planets As larger planets grow in their protoplanetary discs, they could shepherd the flow of dust, leading to the formation of a smaller planet between them, it was recently discovered. This ‘sandwiched’ planet formation could be responsible for the rings seen in the discs, where the dust has been cleared from a specific region. Ham radios find solar flares Shortwave ‘ham’ radio operators around the world have begun experimenting with a new way of detecting solar flares. Shortwave radios bounce signals off the ionosphere; when this layer of the atmosphere is hit by a solar flare it expands, doppler-shifting the signals, thus revealing solar activity. Visit hamsci.org for details. Planetary spiral Giant exoplanets are responsible for sending their protoplanetary discs into a spin, it has now been confirmed. Spiral…

In the 23 September 1991 episode, Patrick looked at the exciting discovery of what appeared to be the most luminous object ever seen, that hadjust been found by the Infrared Astronomical Satellite (IRAS). During a survey to measure the redshifts of 1,400 galaxies, the team found one, IRAS F10214+4724, appeared to be considerably further away than expected. Its light had set out when the Universe wasjust 80 per cent its current age and had travelled 16 billion lightyearsto reach Earth. At that distance, the galaxy would be brighter than 30 trillion Suns or 30,000 times that of the entire Milky Way. Yet despite being so luminous it was also practically invisible, as 99 per cent of its light was in the infrared. Initially, the leading theory was it was a…

Emailyour queries to scopedoctor@skyatnightmagazine.com I'm buying my first new telescope in 10 years and am thinking about a Celestron NexStar 130SLT, but what else could make my life easier, given I have limited spare time? BEN FRIEL There is a fantastic choice of telescopes and mounts these days and with limited spare time, a simple-to-use but productive instrument makes most sense. A telescope with good light grasp and a moderate focal length, coupled with a Go-To altazimuth mount would be a great choice. The Celestron NexStar130SLT you are considering hits this sweet spot in many ways: the aperture is a generous 130mm without the telescope being unwieldy, while the 650mm focal length makes it suitable for a wide range of observations covering deep-sky, lunar and planetary objects. The Go-To mount,…

There are no bright, naked-eye comets on the horizon, but 103P/Hartley – a short-period comet that rounds the Sun every 6.4 years – could be favourable in September. It will be visible in the late evening/early morning sky as a seventhmagnitude object, drifting through Perseus and into Auriga, passing Capella before dropping down into Gemini. Too faint to see with the naked eye, it should be an easy target for binoculars and small telescopes. Its maximum brightness coincides with the presence of a big, bright Moon, which will affect its appearance, but it will still be worth a look. Although the lack of bright comets is disappointing, there are plenty of meteor showers to enjoy with minimal interference from the Moon: DR ACONIDS: peaking on 8–9 October, expect to see…

BBC Sky at Night MAGAZINES 16-PAGE CENTRE PULLOUT BRILLIANT VENUS After its beautiful evening appearance during the first half of 2023, Venus is now dominating the early morning sky BINO BEAUTIES Hunt for widefield gems around Aquarius FIND A CITY ON THE MOON! Spot the lunar light effect on 8 September About the writers Astronomy expert Pete Lawrence is a skilled astro imager and a presenter on The Sky at Night monthly on BBC Four Steve Tonkin is a binocular observer. Find his tour of the best sights for both eyes on page 54 Also on view this month… ✦ A busy month of meetings for the Moon ✦ Neptune at opposition ✦ Catch asteroid Thisbe ✦ Mercury at greatest western elongation Red light friendly To preserve your night vision,…

BEST TIME TO SEE: Various times The full Moon on 29 September occurs 32 hours 52 minutes after lunar perigee, the point where the Moon is closest to Earth in its orbit. Also known as a supermoon, it will appear subtly larger and brighter than average, and is the last one this year. This full Moon is also less than a week after the September equinox, which occurs at 07:50 BST (06:50 UT) on 23 September and as the closest full Moon to it, it's the Harvest Moon for 2023. The Harvest Moon's name is quite appropriate in that it references a real effect. During its near-to-full phases around the September equinox, the differences in time between moonrises from one day to the next are at a minimum. This is…

Vitello Type: Crater Size: 41km Longitude/latitude: 37.6° W, 30.4° N Age: Around 3.8–3.9 billion years Best time to see: 3 days after first quarter (25–26 September) or 2 days after last quarter (9–10 September) Minimum equipment: 50mm refractor Vitello is a 41km crater located on the southern border of 380km-diameter Mare Humorum. Positioned in the southwestern quadrant of the Earth-facing side of the Moon, it's best seen as the Moon is in its waxing gibbous to waning crescent phases. The phases that occur near and after last quarter are better placed in the morning sky at this time of year, so a late night or early start will get you the best views of this region of the Moon. Vitello is impressive in that it's fairly old, but retains many of its youthful looks. Its…

On 24 September, NASA's OSIRIS-REx mission will finally arrive home, the culmination of its seven-year-long journey to asteroid Bennu and back. The Origins Spectral Interpretation Resource Identification and Security - Regolith Explorer, to give OSIRIS-REx its full title, will be carrying with it an estimated 250g of dust and pebbles which it carefully gathered from the asteroid's surface back in October 2020. This precious cargo is being eagerly anticipated by planetary geologists around the globe, as it will be one of just a handful of pristine samples taken directly from another Solar System body. That may not be the case for long, though. Recent years have seen the number of such sample-return missions increase, heralding a new age for this particular field of space science. These missions provide a hugely…

1 Astro Essentials 60mm guidescope Price £99 • Supplier First Light Optics www.firstlightoptics.com The long focal length of this guidescope means it's compatible with almost all guide cameras, while its wide field of view and fast f/4 focal ratio means you should easily be able to pick out a guide star. Guide cameras can push-fit into the 1.25-inch eyepiece clamp or screw in via the integrated M42 thread. 2 Legami eraser set Price £4.50 • Supplier Cult Pens www.cultpens.com Each of these colourful erasers are shaped to look like one of the eight major planets, plus a rocket to visit them in. A wonderful gift for space-enthused children as they head back to school. 3 Askar 5-in-1 M54 filter drawer Price £155 • Supplier 365 Astronomy www.365astronomy.com Swap between filters…

When to use this chart 1 Sept at 00:00 AEST (14:00 UT) 15 Sept at 23:00 AEST (13:00 UT) 30 Sept at 22:00 AEST (12:00 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. SEPTEMBER HIGHLIGHTS Comet 2P/Encke is one of the shortest-period comets (3.3 years) and has been observed for over 300 years. It's best observed in the early dawn above the northeastern horizon. Starting the month in Auriga, it heads towards Castor, being closest on the 12th (1° north), around 10th magnitude. The 22nd sees Encke around ninth magnitude, just above the horizon, an hour before sunrise. It continues to drop into the dawn glow…