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Episode 112 – Brown Dwarfs, Dark Matter and Dark Energy

By Gurbir Dated: March 15, 2024 Leave a Comment

This episode was recorded in Tenerife with Professor Eduardo L Martín who is based at the Instituto de Astrofísica de Canarias. He is working on the European Space Agency’s mission, Euclid.

In time Euclid will shed light on both dark matter and dark energy. It was launched in July 2023 and arrived in its L2 orbit a month later. It has just two instruments which will produce a high-resolution 3-D map of a third of the sky, stretching back 10 billion years during its initial 6-year operational lifetime.

Professor Martín is not part of the Euclid Consortium the around 2500 scientists and engineers from more than a dozen countries who operate the Euclid Mission. He is one of the two Euclid mission Independent Legacy Scientists. Professor Martín is a specialist in substellar bodies, that is celestial bodies with a size about that of Jupiter but with around 50 times its mass. When initially theorised in the 1960s they were called Black Dwarfs but renamed in the 1970s by Jill Tarter as Brown Dwarfs.

Brown Dwarfs generate energy only through gravitational compression, not nuclear fusion. There is an overlap in surface temperature between young brown dwarfs and old very low-mass stars. Martín and his collaborators have developed spectroscopic methods to distinguish brown dwarfs from stars, in particular the Lithium test. More about this interesting role of Lithium in cosmology in Professor Martín’s book published in 2023 by the Institute of Physics, entitled “Lithium Across the Universe“. You can download several free-to-read chapters – here.

Brown Dwarfs emit mostly in the infrared not optical light as our sun. One of the two instruments on Euclid operates in the infrared and can detect these “dark ultracold objects of substellar mass“. Does Professor Martin think Euclid will find Brown Dwarfs? He told me in this recording, “that is what I put in the proposal so we had better do now”. He is supported by a postdoc Marusa Zerjal and a student Diego Martin, funded by the European Research Council.

The first images were released in November 2023. The spacecraft and its instruments are operating well and sending data. More about the Euclid mission, images released so far and a summary of the attributes of Normal Matter, Dark Matter and Dark Energy below.

Episode112 ESA’s Euclid Mission with Professor Eduardo Martin

Perhaps the most pressing question for astrophysicists is what is the cosmos made of. They have known for a long time that visible matter accounts only for the 5%, Dark Matter, 27% and Dark Energy 68%. Currently, most of the attributes of Dark Matter and Dark Energy remain a mystery. Helping to shed some answers to these questions is Euclid’s primary goal.

The visible matter is something we are surrounded by. It responds to all 4 known forces, electromagnetic, gravitation, and the strong and weak nuclear force. Dark matter is not dark, it’s invisible and is only detected through its gravitational influence on the matter we can see. Gravitational lensing is one manifestation.

Whereas gravity is a force of attraction, Dark Energy is repulsive, powering the expansion of the Universe. Its effects are observed by monitoring type 1a supernovae in distant galaxies. Some scientists consider Dark Energy as the Cosmological Constant that Einstein initially added and then removed from his General Theory of Relativity. The Cosmological Constant is now considered by some as the 5th fundamental force, after gravity, electromagnetism, and strong and weak nuclear forces.

  • Horse head Nebula. Credit ESA
  • Globular Cluster NGC6397. Credit ESA
  • Irregular Galaxy NGC6822. Credit ESA
  • Spiral galaxy IC342. Credit ESA Credit ESA
  • Perseus Cluster. Credit ESA

Summary of attributes for Normal Matter, Dark Matter and Dark Energy

AttributeNormal MatterDark MatterDark Energy
Formation TimeShortly after the Big BangLikely formed shortly after the Big BangBelieved to have originated with the expansion of the universe
LocationEverything we can see including Galaxies, stars, planets and the interstellar mediumPrimarily in galactic halos, halos around galactic clusters and permeates the universeHomogeneously distributed throughout space, associated with vacuum energy
Observational EvidenceEmission and absorption spectra, visible light, X-rays, cosmic microwave backgroundGravitational effects on visible matter, galaxy rotation curves; Dark matter inferred from galaxy cluster dynamics by Fritz Zwicky, 1933). Galaxy rotation curves suggest dark matter and the work of Vera Rubin from the 1970s.
Observation of gravitational lensing.
Acceleration of cosmic expansion, distant Type 1a supernova observations by Saul Perlmutter, Brian Schmidt, Adam Riess (1998-1999).
In time, it may turn out to be the 5th fundamental force.
Interaction with Electromagnetic ForceStrong interaction, contributes to various spectra and emissionsWeak or non-existent interactions with light and other EM wavesWeak or non-existent interactions with light and other EM waves
Interaction with Gravitational ForceExperiences gravitational attraction with other matterExperiences gravitational attraction, influencing cosmic structures. Exhibits a repulsive gravitational effect, driving cosmic expansion
Percentage Composition in the Universe~4.6% of the total mass-energy content~26.5% of the total mass-energy content~68.9% of the total mass-energy content
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ISRO in the news

By Gurbir Dated: March 6, 2024 Leave a Comment

Three stories in the news related to the Indian Space Programme

1. The ISRO Chief ISRO chief S Somanath was diagnosed with more than 6 months ago. He saw him in Baku during IAC2023 – he looked well but was working to a hectic schedule – which is normal. The report below indicates that he is getting treatment and getting on with his job as normal. More here Times of India

2. A bit more detail but no schedule – for India’s lunar sample return mission. Two launch vehicles will be needed to complete the job. First the heavier LVM-3 with 3 parts – a propulsion module to get to the Moon, a Descent module to land and an Ascent module to come back to lunar orbit. The second will use the GSLV and contains two parts. A transfer module – transfers lunar samples in lunar orbit from the Ascent module and heads back to Earth and the second – a reentry module. This is part of the transfer module that will deliver the samples to the Earth’s surface.

No details of the landing point. It could be mainland India, the Indian Ocean or maybe the Australian outback. More on Reddit here

3. ISRO has published some details on the proposed design of the Next Generation Launch Vehicle. Three key innovations (a) use of methane with LOX – very popular at present (b) Reusable, at least in part using a barge at sea (c) The absence of a cryogenic stage, a technology that ISRO has spent lots of time and money on over the last 3 decades

The picture below from @ISROSpaceflight via Twitter/X

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Why India signed the USA’s Artemis Accords and why now?

By Gurbir Dated: September 22, 2023 Leave a Comment

First published in the Autumn 2023 edition of Room. Space Journal of Asgardia.

Updated 23rd September 2023 – Astrotalkuk.org Read full text online below or download pdf here.


During India’s Prime Minister Modi’s 4-day visit to the USA from 20th to 24th June 2023, India signed the Artemis Accords. Why did India do that, what was in it for the USA and why did it happen then?

The Artemis Accords is a non-binding bilateral agreement (thus not international law) between the USA (NASA and the USA State Department) and each nation that signs up. It specifies 10 principles, ostensibly consistent with the United Nation’s 1967 Outer Space Treaty (OST), for international cooperation in the civil exploration of the Moon, Mars, Comets and Asteroids. It was announced on 13th October 2020 during the 71st International Astronautical Congress in Dubai. The initial number of 10 countries (Australia, Canada, Italy, Japan, Luxembourg, the United Arab Emirates, the United Kingdom and the United States) has gradually grown since. On 22nd June 2023, India made it to 27 countries. Since then Argentina and Germany have signed bringing the total to 29.

Why did India sign when it did? The technologies for commercial exploitation of resources on the Moon and other celestial bodies is now sufficiently mature that every nation that can is rushing headlong to get their stake in the ground. The Moon has a very large deposits of many commercially sought after materials substances for example Helium-3 and Lithium. The technology to mine, refine and transport back to Earth is not yet present. But when it arrives, those nations with a presence on the Moon will be ready.

Indian Ambassador Taranjit Sandhu, signs the Artemis Accords on 21 June, 2023. US Department of State Deputy Assistant Secretary for India, Nancy Jackson (left), NASA Administrator Bill Nelson, and ISRO Space Counsellor, Krunal Joshi.

The number of missions beyond Earth’s orbit, especially to the lunar surface is expected to dramatically increase in this decade. Out of the six lunar landings scheduled in 2023, so far Japan’s (Hakuto-R) failed in April, Russia’s Luna 25 was lost in August. India succeeded with its first soft landing with Chandrayaan-3 on 23rd August 2023. Another from Japan (SLIM), and two NASA commissioned, private sector missions (Nova-C IM-1 and Peregrine) could land before the end of 2023.

As more companies and countries gain a foothold on the Moon, they will benefit from an agreed set of common rules. That is where the Accords come in. The Accords require all countries that sign to abide by a number of principles when operating in space beyond the Earth. The 10 principles include:

1. Peaceful uses: cooperative activities are exclusively for peaceful purposes and in accordance with international law.

2. Transparency: commit to broad dissemination of information regarding their national policies and exploration plans. Agree to share scientific information with the public on a good-faith basis consistent with Article XI of the OST.

3. Interoperability: agree to develop infrastructure to common standards for space hardware and operating procedures that include fuel storage, landing systems, communication, power and docking systems.

4. Emergency Assistance: commit to offering all reasonable efforts to render assistance and comply with the rescue and return agreement as outlined in the OST.

5. Registration of Objects: agree to register and publicly establish which space objects, (on the surface, in orbit or in space) are owned and operated by who.

6: Release of Scientific data: commit to openly sharing scientific data arising from space exploration missions. Not mandatory for private-sector operations.

7. Preserving Outer Space Heritage: undertake to ensure new activities help preserve and do not undermine space heritage sites of historical significance.

8. Space Resources: signatories affirm that extraction of resources does not inherently constitute national appropriation under Article II of the OST.

9. Deconfliction of Space Activities: undertake exploration with due consideration to the UN guidelines for the long-term sustainability of Outer Space Activities as adopted by United Nations Committee for Peaceful Uses of Outer Space (COPUOS) in 2019. Activities, where potential harmful interference could occur, should be restricted to pre-identified Safety Zones. The size, location and nature of operations in a Safety Zone should be notified to all signatories and the UN Secretary-General.

10 Orbital Debris: signatories agree to limit harmful debris in orbit through mission planning that includes selecting flight orbital profiles that minimise conjunction risk, minimising debris release during the operational phase, timely passivation and end-of-life disposal.

The current and next decade will see multiple nations arriving at the Moon, near-Earth asteroids and comets for space exploration and commercial exploitation. The accords define a set of guidelines, principles, and a set of common norms and behaviours that are mutually beneficial when operating missions far from Earth. But why not simply sign up for the United Nations Outer Space Treaty and the Moon Treaty? Whilst the Outer Space Treaty, established in 1967 has 113 signatories, The Moon Treaty (1979), only 18 parties have agreed to be bound by it. India is one of those 18 but has not yet ratified.

Why have so few nations signed up to the Moon Treaty? All to do with the legal status of extracting resources from the Moon. Article I of the OST describes outer space which includes the Moon and other celestial objects as being the “province of all mankind” and “is not subject to national appropriation”. Further, article II in the Moon Treaty explicitly forbids any part of the Moon from becoming the property of a nation, a private organisation or a person. Countries don’t sign up to the OST because they consider it will restrict their future potential commercial operations in space and especially on the lunar surface. The Artemis Accords, on the face of it, offer a workaround. All member nations affirm that extraction of resources “does not inherently constitute national appropriation under Article II of the OST.” In other words, you can extract and own the resources but have no claim of ownership of the place from which they came. How legally robust that is, only time will tell. The Artemis Accords (now with 29) already has more signatories than the Moon Treaty (with 18).

But there is another reason why nations may join the Artemis Accords. As the name suggests, The Artemis Accord signatories get to join the already International “Artemis Programme”. What that actually means will depend on the capability each nation can bring to the table. Even a small nation, new entrants like Romania and Rwanda with minimal capability will have access to and opportunities for cooperation. A key benefit of any club membership is access to other members of that club.

Why has India joined only now? Artemis Accords has a competitor. Less than a year after the Artemis Accords were announced, China and Russia established the International Lunar Research Station. The ILRS is a lunar base designed for conducting scientific research. It includes all the support facilities on the lunar surface, in lunar orbit and transport between Earth and the Moon. Two years on, only four nations have joined (Pakistan, the United Arab Emirates, South Africa and Venezuela) China and Russia.

India has always remained non-aligned. It has kept its options opened and lipped between USSR, Europe or the USA – wherever its interests were best served at the time. A lesson learnt during the international sanctions regime following India’s nuclear tests in 1974 and 1998. India’s first rocket launched into space in 1963 came from the USA. Its first satellite and first astronaut went to Earth orbit on USSR launch vehicles. India used the Space Shuttle to launch one of its communication satellites in 1983, collaborated with NASA on its first Moon mission in 2007 and is preparing to launch a joint ISRO/NASA Earth observation in 2023. ISRO has launched European satellites and engaged the European Ariane 5 to launch its heavy GEO satellites. Over the last 5 years, Russia has been assisting ISRO with its Gaganyaan (Human Spaceflight) programme.

Sanctions imposed on Russia following its invasion of Ukraine have severely diminished its ability to collaborate in space. Right now and in the foreseeable future, India sees more opportunities with the USA than with Russia.

The geopolitical and economic landscape of mid-2023 was just right for the USA to invite India and India to accept. It was in USA’s interest to get India onboard. It is a win-win situation. As a result, India will have access to technology and know-how for its upcoming high priority Human Spaceflight Programme, Gaganyaan. For the USA, India joining is a huge boost for the Accords which will motivate more countries to join the Accords rather than the ILRS. Setting the Accords on the road to becoming the de facto standard.

The principles of the Accords are said to be “grounded” in the OST and the Moon Agreement, but the Accords is not a United Nations product but has its origins in the USA State Department and NASA. If and when France and Italy sign-up, the Accords will become the default go-to framework for international collaboration in space. In the process, pretty much side-lined the ILRS. A geopolitical win for the USA.

Recognising the importance of India signing the accords, India extracted significant concessions that included space and non-space-related benefits. Although diplomatic ambiguity obscures any direct connection to the significant concessions.

Additional USA-India agreements announced at the same time include :

a NASA/ISRO joint mission to the ISS in 2024 (this tight timeline may not be met but more immediately this may ‘facilitate” NASA support for India’s Gaganyaan programme)

 support India’s membership of the Mineral Security Partnership

establish a joint Indo-US mechanism between industry, government and academia for artificial intelligence, information science and quantum information.

A new public-private cooperation forum for the development of advanced communication using 5G and 6G.

A multimillion-dollar investment to establish a semiconductor ecosystem which will include semiconductor assembly and test facilities in India.

In addition to collaborative activities in space, and bilateral economic opportunities, perhaps the most significant concession was the 4 days state visit by India’s prime minister to the USA and the opportunity to address a joint meeting of the US Congress. A public endorsement from the president of the most powerful democracy to the prime minister of the largest one. Particularly useful for a prime minister looking to win a 3rd term in elections in India in 2024. In return, the USA, through India’s membership, boosted the future success of the Artemis Accords and the Artemis Programme.

However, the Artemis Accords are not legally binding. It is not a treaty or an agreement but a set of Accords. There is no compliance or enforcement mechanism. Despite it being a product with roots in one country, currently, it is the only framework that can offer practical value and tangible benefits to all nations with space missions beyond the Earth.

In the USA, the Wolf Amendment legally restricts how NASA can collaborate with Chinese Space missions. Whilst the Wolf Amendment does not legally prohibit China from signing the Accords, in practice that is the effective outcome. Over the last decade, China checked off some astonishing accomplishments in space. Highly successful human space programme, a space station in Earth orbit, a Lunar rover on the far side of the Moon and a soft landing of a rover on the surface of Mars. China sees the Artemis Accords as an instrument to sustain US dominance whilst undermining China’s space ambitions. All this whilst Russia’s space programme has experienced a significant decline resulting from the sanctions following its invasion of Ukraine. Russia may be associated with the heady days of Sputnik and Gagarin but now China has surpassed Russia and is second only to the USA. Whilst the Wolf Amendment remains, it is unlikely in the short term that China will join and thus prevent the Artemis Accords from being adopted as a near-global framework for responsible behaviours in space.

Just as in Star Trek, the Khitomer Accords of 2293 were followed by the Second Khitomer Accords in 2375. So as the Artemis Accords attain wider engagement, they will evolve over time too.

That the Artemis Accords is a product of one country, the USA is its major drawback. To succeed in its ambition to be a global “common set of principles to govern the exploration and use of space” the Artemis Accords require an internationally inclusive appeal. In a decade or two when the Artemis programme exists only in the rear-view mirror of space history, the Artemis Accords could finally become the global governance framework for all nations exploring and exploiting space beyond Earth orbit. The content could remain substantially unchanged but politically transformed with a new name and placed under the auspices of the United Nations.

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AI-Generated Audiobooks. Discount codes

By Gurbir Dated: June 5, 2023 Leave a Comment

I created a couple of audiobooks using Google AI-generated voices. Surprisingly good and with time this technology will only get better! Some discounts for books, books and audiobooks are below.

1. The story of the founding of the British Interplanetary Society in Liverpool in 1933 as re-called by its first honourary secretary – Leslie J Johnson. My Personal History of The British Interplanetary Society: Liverpool 1933 to 1937. The book contains a letter written by then-16-year-old Arthur C Clarke in 1934. In that letter, he has a swing at the Daily Mail! So precient was Aurthur –  well he was a futurist! Here is his letter in audio  https://lnkd.in/eGXkpH2Y

2. So there was this Indian rocket experimenter called Stephen Smith (yes he really was Indian – his dad came from Lincolnshire) experimenting with rockets between 1934 and 1944 in Calcutta. More about his story here India’s Forgotten Rocket Pioneer.

Get them directly from Google Play



Leslie Johnson: https://lnkd.in/eEpWV4Ka


Stephen Smith: https://lnkd.in/e2Bfie2a


For ebooks and print books use the discount codes below valid for the whole of June 2023.

The latest book – Atlas of Space Rocket Launch Sites. It really is an atlas – tons of pictures and maps about most of the launch sites around the world. It includes Sohae Satellite Launching Station in North Korea where its first spy satellite launch attempt on 31/5/2023, failed.

The following discount codes, use at checkout are valid until 30th June 2023.

“66_virtual” for 66% discount on all ebooks
“33_physical” for 33% discount on all paperback and hardback

Visit this page for all the codes and links to all the books https://lnkd.in/etr6RzSK

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