Today is “International Dark Matter Day” (who knew?). Why not join renowned astrophysicist, Prof Katherine Freese from the University of Texas at Austin, as she recounts the ongoing search for understanding the nature of dark matter – the mysterious substance that constitutes most of the mass in the universe. This is just one of many events that form part of “Samhain agus Science festival” which brings together researchers from Dublin Institute for Advanced Studies and around the world for a series of free online events that explore the dark side of science and Celtic heritage. Some of the events include: the ins and outs of Irish words through time, and finding mysterious missing black holes in the stellar graveyard. For the full programme list and and to register to attend visit: www.dias.ie/samhainagusscience.

If you are one of the growing number of people who believe door wreaths are not just for Christmas, then check out the autumn collection by Celine’s Flowers. Crafted in its Dublin studio, the “Autumn Breeze” wreath will add some character to your doorscape. Fruits of the forest and dried lavender are the inspiration for this wreath. Created with lavender, faux roses, a berry branch, allium and foliage, this wreath evokes seasonal colour and tones. www.celinesflowers.ie

For an easy (and calorific!) treat this weekend pick up some Krispy Kreme limited edition Halloween doughnuts. The new range includes the Jack O Lantern and other ghoulish designs such as the Creepy Cobweb, Vampire Bat and Spooky Sprinkles doughnuts, from €2.65. Gooey – oozing different flavoured fillings, smothered in frosting or sprinkles – they are available to buy in-store at Blanchardstown and The Rocket at Dundrum Town Centre.

Halloween at Killruddery, Co Wicklow marks Samhain, the Celtic new year, with several seasonal activities and competitions this weekend. Visitors can pick and carve their own pumpkins at their carving stations (pumpkins cost €6), while enjoying some mulled apple juice or cider with wood fired pizza. Visitors are invited to post a “Pumpkin Patch” moment on Facebook or Instragram (#Killruddery #FarmShop) to be in with a chance of winning a Killruddery Farm Shop gift hamper. Killruddery is also teaming up with the Happy Pear to host a pumpkin pie competition on October 31 at its Grain Store Restaurant. Steve and Dave Flynn (the Happy Pear) will be taste-jury and judges. Pies can be vegan/non-vegan and should be dropped off at the Grain Store between 10am and 11am, winners will be announced at 12pm. Entry is free and the winner will receive a Killruddery gift voucher; www.killruddery.com.

Wild Lights has opened at Dublin Zoo this week with a new theme and will take visitors on a global adventure taking in some famous landmarks and iconic symbols along the walking trail. Over 1,000 illuminated lanterns will transform the zoo which will host Wild Lights every Thursday, Friday, Saturday and Sunday from now until January 9. Admission is €22 for adults and €18 for children with concessions available; www.dublinzoo.ie.

Droichead Arts Centre is planning a spooky Halloween for all ages this weekend. “Tailtiu’s Tall Tales” is an interactive collection of short stories brought to life with audio installations; Alice and the Wolf, a modern retelling of the classic fairytale by Barnstorm Theatre, questions what happens when the people you meet online come looking for you in real life? Who can you trust, and who is the Big Bad Wolf? This re-telling is both funny and full of dangerously dark twists. If you can’t get to Droichead Arts Centre, Lost Hearts is an online event by The Curious Ensemble, filmed in the magnificent setting of Roundwood House, Mountrath, Co Laois. Set in 1903, Lost Hearts is about Stephen Elliot, who is rapidly descending into madness and opium addiction. In an attempt to arrest his decline, psychiatrist DoctorOlsen utilises hypnosis to delve deep into the young man’s suppressed memories. What is revealed is a terrifying episode from Stephen’s childhood, when, as a traumatised orphan, he was sent to live with his reclusive Uncle at the remote Aswarby Hall. For further information and bookings, go to www.droichead.com.

Celebrating the pagan festival Oíche Shamhna on Inis Mór, the largest of the three Aran Islands, has always been very popular. Pop over by ferry on Saturday, October 30 and you’ll find a Halloween market at the local hall in Kilronan village, followed by “taisce agus tríocha na Samhna” or a Halloween treasure hunt, which will run from 3.30pm until 4.30pm, the charge for this is €10 per family. Throughout the island, visitors will see scarecrows in fields and front gardens of homes, part of an island competition while in the local pubs, Halloween fancy dress competitions will be in full swing. www.aranislandferries.com

If you need some last minute decorations, try TK Maxx (my new Saturday addiction) and Homesense, where tablescapers can pick up plush velvet pumpkins (just like Mrs Alice’s) ceramic pumpkins, orange throws (for draping on chairs), and Damien Hirst-inspired sparkly skulls; www.tkmaxx.ie.

For those wanting to stock up on treats for doorstep callers ahead of Sunday, Swiss chocolatier Lindt & Sprüngli has opened a new permanent store in Kildare Village. The only store the brand has in Ireland, it will offer assorted bars, sharing boxes and beautifully packaged gifts as well as the largest “pick and mix” Lindor selection in the country. What’s your favourite – orange, milk, salted caramel, double chocolate or hazelnut? The store also offers drinks and ice cream. Do pop in if you are at Kildare Village over the weekend; www.tbvsc.com.

If you want to escape the Halloween hullabaloo a new haunt has opened at the 275-year-old Queens pub in Dalkey, Co Dublin. It has recently undergone an extensive refurbishment and the stylish redesign is complemented by a new menu created by chef Michael Morrisroe (formerly of The Strawberry Tree in Co Wicklow and Restaurant Patrick Guilbaud, Dublin). His menu, prioritising Irish produce, includes an impressive selection of savoury tapas. Visitors will also find The Vico, a new weekend space upstairs at the Queens; www.thequeens.ie.

Into the Ether is a new lifestyle brand by Irish wellness entrepreneurs Annie Kirwan and Lee Tracey, specialising in sustainable, locally-made self-care items, gift boxes and homewares. Items include handcrafted 24-carat gold necklaces with crystals, illustrated journals and diaries, handmade soaps, bath salts, essential oils, and organic cacao blocks. Particularly appropriate this weekend are its Dark Moon candles, €22.50, with the scent of bergamot, lime, mandarin and patchouli. These are also included in The Moon Box, €104.95. This includes a moonology book, an Into the Ether 2022 Diary, (with lunar phases and moon calendar), and sustainable Palo Santo for dark and full moon ceremonies and circles. Into The Ether is available to buy on intotheether.ie, and from its new experiential retail store on Waterloo Lane, Ballsbridge, Dublin 4.

Arkle Bar & Restaurant – named after the famous racehorse – is a new addition to the Maynooth food scene. Interior designer Michele Broderick is responsible for the decor (a mix of antique mirrors, decorative wallpapers, luxe fabrics) while executive chef Bernard McGuane has overseen the menu. There’s a tempting bar and cocktail menu as well as The Enclosure restaurant (also housed within the bar), which offers guests a variety of culinary experiences using the finest, locally-grown produce, free-range meats and the freshest seafood. Chef McGuane’s main priority at The Enclosure and Arkle Bar is on deliciousness, with a focus on bold flavours from simple ingredients. He can be heard on the pass saying “Make sure it’s delicious!”. www.glenroyal.ie

Streaming on Netflix from today, Friday, October 29, is Witness to the Future directed and produced by Johnny Gogan, about the Irish essayist and human rights champion Hubert Butler (1900-1991). He wrote about the “inter-war Jewish crisis”, smuggled Jewish people into Ireland from Vienna before the war and, after the war, exposed the genocide of Jews and Serbs in World War II Yugoslavia. He anticipated the re-emergence of these animosities in a future Balkan War. Butler paid a price for these insights in his home country when, in 1952 he was targeted by the authorities. The film explores why Butler was 50 years ahead of his time and why he has been celebrated as a champion of pluralism; www.netflix.com.