The Euclid spacecraft launched over a week ago so so here’s a short video explaining its trajectory and what it will do over the next weeks and months.
Archive for the Euclid Category
Euclid Update
Posted in Euclid, The Universe and Stuff with tags ESA Euclid, Euclid, L2 on July 10, 2023 by telescoperBrainstorm Flash
Posted in Biographical, Euclid, Maynooth, The Universe and Stuff on July 6, 2023 by telescoperThe media activity surrounding the launch of Euclid on Saturday continues. Yesterday a piece by yours truly appeared on RTÉ Brainstorm with the title All you need to know about Euclid’s six year space mission. It subsequently got picked up by the main RTÉ News website on their News Lens panel, although it’s in second place after a story about a hot-dog eating competition:

P.S. There is also piece in siliconrepublic based on an interview with me here.
Countdown to the Euclid Launch
Posted in Euclid, The Universe and Stuff with tags ESA Euclid, Euclid, Falcon-9, SpaceX on July 1, 2023 by telescoperToday’s the day! Weather permitting, of course, all eyes will be on Cape Canaveral for the launch of the Euclid satellite later this afternoon (as reckoned in Ireland). You can watch the launch on YouTube via the following stream (but it won’t start until 15.30 Irish Time; 16.30 CEST):
The Key Events to look for in local time are:
16:12 Euclid launch on SpaceX Falcon 9
16:53 Separation of Euclid from Falcon 9
16:57 Earliest expected time to establish communication with Euclid
After that, the mission is handed over to the ESA Space Operations Centre in Darmstadt, Germany as it sets out for the Sun-Earth Lagrange point L2. Approximately four weeks after launch, Euclid will enter in orbit around this point, which is located at 1.5 million km from Earth, in the opposite direction from the Sun. Once in orbit, mission operators will start verifying all the functions of the telescope. During this, residual water is outgassed, after which Euclid’s instruments will be turned on. Between one and three months after launch, Euclid will go through several calibrations and scientific performance tests and get ready for science. The telescope begins its early phase of the survey of the Universe three months after launch. There will be a preliminary release of a small amount of data in December 2024, but the first full data release – DR1 – will take about two years.
UPDATE: All critical stages of the launch passed satisfactorily, and contact has been established with the ground control. Euclid is now on its way to L2. Bon Voyage, Euclid!
Pushing Euclid
Posted in Biographical, Euclid, Science Politics, The Universe and Stuff with tags Euclid, Morning Ireland, NewsTalk, Sunday Times on June 30, 2023 by telescoperI’ve spent a sizeable chunk of the last two days answering press enquiries concerning the Euclid mission, due to be launch about 24 hours from now. Here is a picture of Euclid in the Falcon 9 fairing, getting ready to be moved to the launch facility. It’s all getting very real!
After talking with their researcher yesterday, this morning I did a short interview on Morning Ireland, which is on RTÉ Radio 1. It was shorter than I imagined because the previous item – about the ongoing ructions at RTÉ over various financial scandals – understandably overran quite a bit. The presenter, Rachel English, was very nice though and I think it went fairly well. I did another short interview on Newstalk Radio on a programme called Hard Shoulder, which took place at 5.48pm. I also spoke to a journalist from the Sunday Times Irish Edition, who I think will run a story on Sunday.
Anyway, the purpose of this media stuff is not to try to grab headlines – my involvement in Euclid is very small, really – but to generate some interest in the hope that Ireland takes a more active role in future space missions. I don’t know whether it will work, but I hope it does, and I feel obliged to try although it has made for a very busy day indeed!
First Impression seeing the Euclid Telescope
Posted in Euclid, The Universe and Stuff with tags Cannes, EPO, Euclid, Thales on June 28, 2023 by telescoperWith just three days to go before the scheduled launch of the Euclid spacecraft on Saturday 1st July 2023, at 1612 Irish Time (GMT+1), the Education and Public Outreach (EPO) team have been continuing to ramp up its social media activity and the second YouTube video has now “dropped” (as you young people say).
This was filmed at Thales Alenia Space in Cannes, France, as members of the Euclid consortium from around the world gathered in anticipation to see the fully-assembled Euclid telescope for the first time as it underwent final tests before its journey to the launch site in Florida.
Euclid’s “Red Book”
Posted in Euclid, The Universe and Stuff with tags arXiv:1110.3193, Euclid, Euclid Red Book on June 27, 2023 by telescoperWith the scheduled launch of ESA’s Euclid mission coming up this weekend, it is perhaps topical to share the document written almost 12 years ago that outlines the design concepts and describes the detailed scientific case. It’s a compendious piece, running to well over 100 pages but, as with virtually everything in astrophysics, the full Euclid Definition Study Report can be found on arXiv.
Here is the abstract:
Euclid is a space-based survey mission from the European Space Agency designed to understand the origin of the Universe’s accelerating expansion. It will use cosmological probes to investigate the nature of dark energy, dark matter and gravity by tracking their observational signatures on the geometry of the universe and on the cosmic history of structure formation. The mission is optimised for two independent primary cosmological probes: Weak gravitational Lensing (WL) and Baryonic Acoustic Oscillations (BAO). The Euclid payload consists of a 1.2 m Korsch telescope designed to provide a large field of view. It carries two instruments with a common field-of-view of ~0.54 deg2: the visual imager (VIS) and the near infrared instrument (NISP) which contains a slitless spectrometer and a three bands photometer. The Euclid wide survey will cover 15,000 deg2 of the extragalactic sky and is complemented by two 20 deg2 deep fields. For WL, Euclid measures the shapes of 30-40 resolved galaxies per arcmin2 in one broad visible R+I+Z band (550-920 nm). The photometric redshifts for these galaxies reach a precision of dz/(1+z) < 0.05. They are derived from three additional Euclid NIR bands (Y, J, H in the range 0.92-2.0 micron), complemented by ground based photometry in visible bands derived from public data or through engaged collaborations. The BAO are determined from a spectroscopic survey with a redshift accuracy dz/(1+z) =0.001. The slitless spectrometer, with spectral resolution ~250, predominantly detects Ha emission line galaxies. Euclid is a Medium Class mission of the ESA Cosmic Vision 2015-2025 programme, with a foreseen launch date in 2019. This report (also known as the Euclid Red Book) describes the outcome of the Phase A study.
arXiv:1110.3193
Euclid was formally adopted as an ESA M Class mission in June 2012. I’ve added the emphasis to the penultimate sentence to draw your attention to the fact that the launch of Euclid is about four years late.
What is Euclid?
Posted in Euclid, The Universe and Stuff with tags EPO, Euclid on June 25, 2023 by telescoperWith less than a week to go before the scheduled launch of the Euclid spacecraft on Saturday 1st July 2023, at 1612 Irish Time (GMT+1), the Education and Public Outreach (EPO) team has been ramping up its social media activity. They’ve even got a blog! Anyway here is a nice video featuring many members of the Euclid Consortium – some of whom gave presentations at last week’s conference – talking about Euclid. The sense of enthusiasm shines through, I think. I will be sharing further videos when they appear.
Copenhagen Looking Back
Posted in Biographical, Euclid, OJAp Papers, The Universe and Stuff on June 23, 2023 by telescoperSo here I am then, back in Maynooth. I had a relatively stress-free trip back, although my plane was a bit late and I had to run through Dublin Airport to catch the Hopper Bus I was booked on. Made it though.
The first thing I want to do is to thank the organizers for what was a wonderful event. I wasn’t able to attend the Euclid Consortium meeting in Oslo last year, largely because it was earlier in the year, in April (i.e. term-time) and I had teaching responsibilities. I gather it was a rather gloomy occasion because there was no concrete plan for the launch of Euclid thanks to the Russian war against Ukraine. I guess few would have predicted then that the 2023 meeting would be just a week or so before a launch on SpaceX!
I have to say the atmosphere was also helped by the excellent weather and very fine catering. The conference dinner was held in the Banqueting Hall, on the first floor of the Hans Christian Anderson Castle which stands at one of the entrances to the famous Tivoli Gardens, a few minutes from the conference venue.

Finally, one other memory that will stay with me for a while. It turned out that the week of the conference coincided with high-school graduation celebrations in Copenhagen, so every day we encountered lots of exuberant and largely inebriated teenagers around wearing funny hats and generally going a bit berserk. They made quite a lot of noise in the evenings, but it was all harmless. You’re only young once!
Having not been at an in-person conference for over four years, it was great to see some new faces and catch up with some people I haven’t seen for a long time. It was especially nice to talk to a couple of members of the Editorial Board of the Open Journal of Astrophysics. It was also nice to talk to some authors. Talking of which, here is Nicolas Tessore delivering a plenary presentation featuring work from one of the papers he has published with OJAp:

Anyway, I was up a stupid o’clock to catch my flight this morning so I think I’ll have a bit of rest and hope for the rain to stop so I can do some shopping.
Euclid Launch Date Confirmed
Posted in Euclid, The Universe and Stuff with tags Euclid on June 20, 2023 by telescoperQuick update from the Euclid Consortium confirming that the launch will take place on Saturday 1st July 2023, at 1612 Irish Time (GMT+1):

If for some reason (such as weather) the launch cannot take place at 11.12 precisely it will be delayed for 24 hours and then launched the next day, 2nd July, at the same time. I’m told that thunderstorms are quite common at Cape Canaveral at this time of year so there may well be such a delay.
P.S. When the Euclid mission was accepted by ESA, over a decade ago, the launch date was envisaged to be in 2020, so it is about three years late.




