Showing posts with label astronomy. Show all posts
Showing posts with label astronomy. Show all posts

25 September 2020

Taking over the night sky


UNTIL relatively recently in human history the night sky remained one of the last unspoilt vestiges of our natural world. From the time of Galileo to the present day, astronomical observations from Earth’s surface have led to exceptional progress in the scientific understanding of the world around us.

Now, just as we enter the third decade of the 21st Century and a dynamic new phase in space exploration and exploitation begins, some of the current capability of astronomical instrumentation from the ground is potentially being endangered by the rapid development of micro-satellite fleets in low Earth orbits (LEO).

In the interests of preserving the ability to make meaningful visual and radio ground-based observations, the International Astronomical Union (IAU) is sounding a clarion call for greater protection and international safeguards.

The IAU claims that if the deployment of mega constellations remains unchecked the view of the night sky will be increasingly impeded by artificial satellites, not only visible to the naked eye but also crossing and scarring professional and amateur time-lapse observations alike with parallel streaks at all latitudes.

SpaceX has already embarked on its ambitious Starlink project to populate the sky with some 42,000 satellites which, together with planned constellations such as those from OneWeb, Amazon and others, means there could one day be more than 50,000 small satellites encircling the Earth at different low altitudes.

These small, mass-produced satellites orbit very close to Earth with the intent to provide speedy internet connections via low-latency signals. But that proximity also makes them more visible and brighter in the night sky. 

Astronomers argue that such constellations will severely diminish our view of the universe, create more space debris and deprive humanity of an unblemished view of the night sky. If these networks come to fruition, they suggest that every square degree of the sky will eventually have a satellite crawling across it throughout the whole observing night.

As space becomes ever more commercialised the speed of such development is quickly overtaking the existing, globally agreed rules governing space activities. Mega-constellations are just one area where new rules of governance are urgently needed. Others include the exploitation of resources on the Moon and elsewhere, preserving peace and resolving disputes, and rules for everyday living in space.

Recognising the urgent need for coordinated action, the space nation Asgardia is organising a second congress in its ‘Paving the Road to Living in Space’ series. Taking place at McGill University in Montreal, Canada, in 2021 (www.alc.space), it will focus on discussing key aspects of space law needed to ensure the success of future space exploits.

Of course, ROOM fully supports the growth and advancement of space technologies and the ensuing benefits they bring to everyday life, business and commerce across the globe.

But it would be ironic indeed if, by exploiting LEO without due responsibility, we neglect to consider the resultant damage to scientific research and a previously unblemished part of our natural environment that deployment of such new technologies could unwittingly deliver.

The urgent question is, do we continue to rush headlong into deploying massive new orbital networks without checks and balances, and with scant regard for the heavens above - or can the global space community approach this kind of thing in a more mature and responsible manner that is fair to everyone?

This editorial by Clive Simpson was first published in the Summer 2020 issue of ROOM Space Journal

 

26 June 2020

Searching for aliens



Allen Telescope array, California, which is part of the search for extraterrestrial intelligence.

SCIENTISTS and astronomers searching for aliens in other parts of the universe have released a catalogue of objects found in space that they hope could help them locate intelligent life.

Breakthrough Listen, an initiative to find signs of intelligent life in the universe, released its innovative catalogue of ‘Exotica’ this week. It contains a diverse list of objects of potential interest to astronomers searching for technosignatures, which might be a tell-tale sign of technology developed by extraterrestrial intelligence.

The catalogue collects over 700 distinct targets intended to include ‘one of everything’ in the observed universe - ranging from comets to galaxies, from mundane objects to the most rare and violent celestial phenomena.

The search for extraterrestrial intelligence (SETI) has been pursued as a serious scientific programme, though at times sporadically, for six decades.

In the last five years, Listen has massively increased the scope of radio (as well as optical) searches, and has developed technology, deployed at giant radio telescopes on three continents, that enables coverage of an unprecedented range of frequencies at high resolution.
                                                                                               
Is there intelligent life in the universe?
No confirmed technosignature has yet been detected and one obvious explanation is that the human race is alone in the universe. On the other hand, in such a vast cosmos it is certainly possible that astronomers have yet to look in the most likely places.

The new Exotica catalogue is the centrepiece of Listen's efforts to expand the diversity of targets and a key principle behind it is the concept of ‘survey breadth’ - the diversity of objects observed during a programme.

This should help astronomers constrain the range of potential habitats for extraterrestrial intelligence, as well as rule out the possibility that any phenomena widely considered natural are in fact artificial.

Conversely, it may identify natural events, or confounding data such as interference, that mimic the kinds of artificial signal SETI researchers are on the lookout for.

The Exotica catalogue contains four categories of astronomical object:

1) Prototypes: a list containing at least one example of every known kind of celestial object (apart from those too transient to present realistic observation targets). Planets and moons, stars at every point of their life cycle, galaxies big and small, serene star clusters and blazing quasars, and more are all included in the list.

2) Superlatives: objects with the most extreme properties. These include examples like the hottest planet, stars with unusually high or low metal content, the most distant quasar and fastest-spinning pulsar, and the densest galaxy.

3) Anomalies: enigmatic targets whose behaviour is currently not satisfactorily explained. For instance, the famous ‘Tabby's Star’ with its bizarre dimming behaviour; ‘Oumuamua’ - the interstellar object that passed near Earth in 2017; unexplained optical pulses that last mere nanoseconds; and stars with excess infrared radiation that could conceivably be explained as waste heat from alien megastructures.

4) A control sample of sources not expected to produce positive results.

Accompanying the catalogue is extensive discussion of classification of objects and a new classification system for anomalies, as well as plans for upcoming and potential observations based on this work.

"Breakthrough Listen has already greatly expanded the breadth and depth of its search," said Yuri Milner, founder of the Breakthrough Initiatives. "The publication of this catalogue is a new and significant step for the programme."

 Pete Worden, executive director of the Breakthrough Initiatives, added: "When it comes to the search for intelligent life, it's vital to have an open mind. Until we understand more about the forms another civilization and its technology could take, we should investigate all plausible targets. Cataloguing them is the first step toward that goal."

Dr Andrew Siemion, leader of the Breakthrough Listen science team at the University of California, Berkeley's SETI Research Center (BSRC), said: "Technosignature searches to date have largely focused on the search for 'life as we know it' on nearby stars - in particular those known to host planets with the potential for liquid water on their surfaces.

“The expanded search capabilities that Breakthrough Listen has made possible allow us to consider a much wider range of possible technology-laden environments.”

The new object list is the first in recent times that aims to span the entire breadth of astrophysics, from distant galaxies to objects in our own solar system. The Listen team has developed it conceptually, compiled it and shared it with the astronomical community in the hope that it can guide future surveys - whether studying life beyond Earth or natural astrophysics - and serve as a general reference work for the field.

Breakthrough Listen is a scientific programme in search for evidence of technological life in the universe. It aims to survey one million nearby stars, the entire galactic plane and 100 nearby galaxies at a wide range of radio and optical bands.

The Breakthrough Initiatives, a suite of scientific and technological programmes, were created by Yuri Milner to investigate life in the universe. Milner, an Israeli-Russian entrepreneur, venture capitalist and physicist, is also the founder of DST Global, a leading technology investor which boasts a portfolio that includes some of the world's most prominent internet companies.

This article by Clive Simpson was first published as a news item on the ROOM Space Journal website on 26 June 2020.

15 April 2020

Traffic lights in the night sky

Starlink satellites leave diagonal lines as they pass through a telescope’s field of view.

UNITL relatively recently in human history the night sky remained one of the last unspoilt vestiges of our natural world. From the time of Galileo to the present day, astronomical observations from Earth’s surface have led to exceptional progress in the scientific understanding of the world around us.

Now, just as we enter the third decade of the 21st Century and a dynamic new phase in space exploration and exploitation begins, some of the current capability of astronomical instrumentation from the ground is potentially being endangered by the rapid development of micro-satellite fleets in low Earth orbits (LEO).

In the interests of preserving the ability to make meaningful visual and radio ground-based observations, the International Astronomical Union (IAU) is sounding a clarion call for greater protection and international safeguards.

The IAU claims that if the deployment of mega constellations remains unchecked the view of the night sky will be increasingly impeded by artificial satellites, not only visible to the naked eye but also crossing and scarring professional and amateur time-lapse observations alike with parallel streaks at all latitudes.

SpaceX has already embarked on its ambitious Starlink project to populate the sky with some 42,000 satellites which, together with planned constellations such as those from OneWeb, Amazon and others, means there could one day be more than 50,000 small satellites encircling the Earth at different low altitudes.

These small, mass-produced satellites orbit very close to Earth with the intent to provide speedy internet connections via low-latency signals. But that proximity also makes them more visible and brighter in the night sky. Astronomers argue that such constellations will severely diminish our view of the universe, create more space debris and deprive humanity of an unblemished view of the night sky. If these networks come to fruition, they suggest that every square degree of the sky will eventually have a satellite crawling across it throughout the whole observing night.

As space becomes ever more commercialised the speed of such development is quickly overtaking the existing, globally agreed rules governing space activities. Mega constellations are just one area where new rules of governance are urgently needed. Others include the exploitation of resources on the Moon and elsewhere, preserving peace and resolving disputes, and rules for everyday living in space.

Recognising the urgent need for coordinated action, next year the space nation Asgardia is organising a second congress in its ‘Paving the Road to Living in Space’ series. It will focus on discussing key aspects of space law needed to ensure the success of future space exploits.

Of course, ROOM fully supports the growth and advancement of space technologies and the ensuing benefits they bring to everyday life, business and commerce across the globe.

But it would be ironic indeed if, by exploiting LEO without due responsibility, we neglect to consider the resultant damage to scientific research and a previously unblemished part of our natural environment that deployment of such new technologies could unwittingly deliver.

The urgent question is, do we continue to rush headlong into deploying massive new orbital networks without checks and balances, and with scant regard for the heavens above - or can the global space community approach this kind of thing in a more mature and responsible manner that is fair to everyone?

Editorial (originally published under the title 'Mega-constellations raise awkward questions for space community') 
by Clive Simpson in the Spring 2020 edition of ROOM Space Journal


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