Profile picture
, 10 tweets, 10 min read
My Authors
Read all threads
My talk on space astronomy & the impact of megaconstellations at #EASLeiden2020 today was recorded & it'll be best to hear the narration to make full sense of it. In lieu of having the recording to hand yet though, here at least are my slides to get some idea 🤷‍♂️

Thread: 1/ Title slide: Space astronomy & the impact of megaconstellatiStock illustration of a low-Earth orbit networkTimelapse photo showing a train of Starlink satellites passiField-of-view of DECam on CTIO 4-m with trails due to the pa
Slides from talk on space astronomy & the impact of megaconstellations for #EASLeiden2020.

cont.

2/ A Starlink satellite train seen from the International SpaceFirst launch of the Iridium telecomms constellation in 1997 An Iridium flare, with sunlight reflecting specularly off onA flare from the ESA/EUMETSAT MetOp-A meteorological satelli
Slides from my talk on space astronomy & the impact of megaconstellations for #EASLeiden2020.

cont.

3/ Three Iridium flares in one image incl Iridium 33, then anotArtist impression of the Russian military satellite Kosmos-2Point of collision between Iridium 33 & Kosmos-2251 & immediDiagrams showing the spread in apogee & perigee of debris fr
Slides from my talk on space astronomy & the impact of megaconstellations for #EASLeiden2020.

cont.

4/ Images showing one of the solar array wings of ESA's SentineImage of ESA's Aeolus satellite, which had to be moved to avDiagram showing the European Space Agency's solar system expSelection of ESA planetary missions to Mercury, Mars, & Jupi
Slides from my talk on space astronomy & the impact of megaconstellations for #EASLeiden2020.

cont.

5/ Four ESA/international solar missions, two in low-Earth orbiFour ESA science missions with highly elliptical orbits thatDiagram showing the European Space Agency's cosmic observersFour ESA/international astronomy missions (Gaia, JWST, Eucli
Slides from my talk on space astronomy & the impact of megaconstellations for #EASLeiden2020.

cont.

6/ Two ESA/international astronomy missions (HST & CHEOPS), oneA sketch showing some ESA/international missions for Earth oThe same low-Earth orbit sketch now with the addition of somPicture showing the NASA/ESA Hubble Space Telescope in low-E
Slides from my talk on space astronomy & the impact of megaconstellations for #EASLeiden2020.

cont.

7/ Diagram showing the history of the orbital altitude of the HImages showing examples of satellite trails observed in HubbOne very bright, out-of-focus satellite trail in a Hubble SpMore examples of satellite trails see in Hubble Space Telesc
Slides from my talk on space astronomy & the impact of megaconstellations for #EASLeiden2020.

cont.

8/ Example satellite trails being seen by the ESA/Swiss CHEOPS Example satellite trails seen by NASA's WISE space telescopeArtist impression of the Chinese Space Station Telescope, a Slide discussing some of the light trail & collision/debris/
Slides from my talk on space astronomy & the impact of megaconstellations for #EASLeiden2020.

Final slides

9/ Discussion of the issues faced by LEO space science missionsSlide of conclusions, recommendations, & observations from mClosing slide of my talk, including a list of people who wer
In principle, #EASLeiden2020 participants can listen back to any of the talks, including this one, until the end of August (?), but I'm not sure if I'll be able / allowed to publish a copy. If not, I'll consider re-recording it myself & publishing that if people are keen.

10/10
Missing some Tweet in this thread? You can try to force a refresh.

Keep Current with Mark McCaughrean

Profile picture

Stay in touch and get notified when new unrolls are available from this author!

Read all threads

This Thread may be Removed Anytime!

Twitter may remove this content at anytime, convert it as a PDF, save and print for later use!

Try unrolling a thread yourself!

how to unroll video

1) Follow Thread Reader App on Twitter so you can easily mention us!

2) Go to a Twitter thread (series of Tweets by the same owner) and mention us with a keyword "unroll" @threadreaderapp unroll

You can practice here first or read more on our help page!

Related hashtags

#EASLeiden2020

More from @markmccaughrean see all

Profile picture
Mark McCaughrean
@markmccaughrean
Fascinating. I didn’t realise wild storks had been extinct in the UK for centuries – there are loads of them around us here in NL.

In particular, there is a large flock in The Hague & strangely enough, they don’t migrate in winter. 1/ theguardian.com/environment/20…
The reason is that storks were domesticated here in the Middle Ages & helped clean away fish remains at the fish market in the Binnenhof. So their ancestors stay here in the winter, instead of migrating to Africa. They’ve been on the coat of arms of Den Haag since 1541. 2/
There is a large flock in the north side of the The Hague & a lady calls them down off their nests atop the apartment buildings to feed them once a day – an impressive sight. I posted a movie of it, but can’t find it now. 3/
Read 5 tweets
Profile picture
Mark McCaughrean
@markmccaughrean
#OTD in 2005, @esa's Huygens probe descended to the surface of Titan as part of the @CassiniSaturn mission.

I wasn't working for ESA at the time, but happily took part in an inadvertent experiment in public engagement that took place that day.

1/
@esa @CassiniSaturn IIRC, as imaging data arrived back from Saturn, they were transferred from @esaoperations to the DISR camera team at @uarizona via ftp.

The ftp account was public & unpassworded, & details of its existence leaked on to the internet.

2/
@esa @CassiniSaturn @esaoperations @uarizona Like many, I went on to the ftp account & downloaded images as they arrived. They were raw & uncalibrated as below, & Huygens was spinning, so it wasn't clear (at least to my untrained eye) that they were showing valleys, channels, & flood plains.

3/
planetary.org/blogs/guest-bl…
Read 20 tweets
Profile picture
Mark McCaughrean
@markmccaughrean
There's a lot of discussion about the dimming of Betelgeuse on astrotwitter at the moment.

This simulation by Bernd Freytag et al. spanning just 16 years shows just how crazily variable red supergiant stars can be due to convection & magnetic fields.

1/
astro.uu.se/~bf/publicatio…
That 3D magnetohydrodynamical simulation using the CO5BOLD code is of a 5 solar mass star with a radius of 600 solar radii (IIRC – need to check) & shows roughly what you'd see with the naked eye. It's very red because red supergiants are cooler than the Sun, around 3500K. 2/

2/
Betelgeuse is larger, ~11–20 solar masses & 900 solar radii (630 million km, 80% of the distance between the Sun & Jupiter), but the same physics applies: huge convection cells from the core to the surface, with magnetic fields threading through, as seen here by Freytag et al. 3/
Read 7 tweets

Embed code for your website

×
Follow Us on Twitter!

Did Thread Reader help you today?

Support us! We are indie developers!

This site is made by just two indie developers on a laptop doing marketing, support and development! Read more about the story.

Become a Premium Member ($3.00/month or $30.00/year) and get exclusive features!

Become Premium

Too expensive? Make a small donation by buying us coffee ($5) or help with server cost ($10)

Donate via Paypal Become our Patreon

Thank you for your support!