Euclid: ‘Dark explorer’ opens its eyes on the cosmos

Europe’s new space telescope, Euclid, has returned its first images

Engineers switched on the cameras of the €1.4bn (£1.2bn) observatory to begin a phase of testing and captured a wide vista of stars and galaxies.

Once properly set up, Euclid will start building a 3D map of the cosmos in an effort to tie down the nature of so-called dark matter and dark energy.

Together, these phenomena appear to control the shape and expansion of everything we see out there.

Quite what they are, however, is highly uncertain.

Neither dark matter nor dark energy are directly detectable, which means Euclid will have to use roundabout methods to glimpse their properties.

It was despatched to an observing position about 1.5 million km from Earth on its night side – a popular location for space observatories because it sits in a gravitational sweetspot that means less fuel is needed to keep a craft on-station.

This place, known as the “2nd Lagrange Point”, also doesn’t suffer from the swings in light and temperature experienced by telescopes orbiting close to Earth.

The new super-space telescope James Webb is another inhabitant of this parking spot.

The test images released by the European Space Agency on Monday come from both of Euclid’s cameras.

Image: ESA/Euclid/Euclid Consortium/NASA

It’s got a visible light (the light our eyes sense) instrument, called simply VIS; and an infrared (longer wavelength light than our eyes will sense) instrument referred to as NISP, or Near-Infrared Spectrometer and Photometer.

The sample pictures from both cameras contain countless stars and galaxies, even though they are tracing a patch on the sky that is smaller than the full Moon.

Interestingly, if you look closely at the VIS imagery, you can see lots of little streaks. These are tracks left by high energy particles, or cosmic rays. They strike the camera’s detectors at all angles to leave lines of various lengths.

When Euclid commences its 3D survey, scientists will remove these artefacts by stacking several exposures on top of each other.

The European Space Agency says mission managers had a bit of a scare when they first examined the VIS pictures because it was evident stray sunlight was getting into the camera through some gap in the hardware.

By turning the space observatory, they were able to block the contaminating light.

The issue should not affect Euclid’s survey, provided the telescope is only used in specific orientations.

Engineers have several more months of commissioning before the telescope can be released to go after its two targets.

Dark matter is the matter that cannot be detected directly but which astronomers know to be there because of its gravitational effects on the matter we can see.

Galaxies, for example, could not hold their shape were it not for the presence of some additional “scaffolding”. This is presumed to be dark matter – whatever that is.

Although this material cannot be seen directly, the telescope can plot its distribution by looking for the subtle way its mass distorts the light coming from distant galaxies.

Dark energy is a very different concept from dark matter.

This mysterious “force” appears to be accelerating the expansion of the Universe. Recognition of its existence and effect in 1998 earned three scientists a Nobel Prize.

Euclid will investigate the phenomenon by mapping the three-dimensional distribution of galaxies.

The patterns in the great voids that exist between these objects can be used as a kind of “yardstick” to measure the expansion through time.

Euclid won’t be able to say definitively “this is the nature of dark matter and dark energy”, but what it should do is narrow the scope of the models and ideas that flood current thinking.

It will focus the attention of theorists and experimentalists.

The development of the VIS instrument was led from the UK.

See more here bbc.co.uk

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Comments (5)

  • Avatar

    Howdy

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    “Neither dark matter nor dark energy are directly detectable, which means Euclid will have to use roundabout methods to glimpse their properties.”
    This is the same sort of reasoning people apply to the reality of the Bible when trying to negate it’s value isn’t it? All wishfull thinking, or just sincere belief, even if misplaced? The difference is, the Bible isn’t causing real hardship and destruction of others’ lives due to stupidity in following it.

    So, no proof of existence of these particles, then how do you find them? Create what you want to see of course! In other words, the results are purposefully generated, made up, conjured from the ether, and all for somebody’s pet project, while the citizens battle economic strife.
    If anybody needs to know how unscientific and wasteful ‘science’ is these days, this the poster for it.

    Science is supposed to benefit all, and no gods in evidence, though there are plenty. Yeah, if only humility meant anything any more, that might happen.
    Science is the biggest religion of all – the biggest hoodwink ever, and the most expensive. Who would ever trust that?

    Reply

    • Avatar

      Herb Rose

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      Hi Howdy,
      I’m surprised that you contend that Biblical belief hasn’t caused hardships. Crusades, pogroms, inquisition dark ages, …
      Herb

      Reply

      • Avatar

        Howdy

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        Fair comment Herb, but claims about the cruelty of the past are not about today. Many atrocities took place in the name of God, and many others, but Humanity is supposed to learn and move on. It hasn’t, yet the past should remain there, not be used for modern day control. Modern Humanity is supposed to be elevated far above those days. They are uncomfortable history.

        Science is supposed to be real, not belief based. Scientific reality is meant to be unchangeable fact, facts that take one closer to actual reality, while belief in the Bible has no factual foundation and can be twisted to use anything, as a means to do anything, to anybody at all, while all based on subjectivity, thus no datum. That’s the difference, hence my comment that science is the biggest religion of all, since it is being perverted to do just what the Bible has done. The only change is that the god is technology, and worship is in any form as long as it looks right, just like the biblical past. It’s just unfortunate that present day makes no difference to a species lost in the desert.

        Reply

        • Avatar

          ecm

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          The Standard Model physicists invented theories based on Big Lies–all which have been swallowed by the gullible public. Create something so stupendous and outrageous that is “shocks” people into a stupor of subservience, and is accepted as the sacred cow of Fact. Dark energy, Dark matter, Big Bang, Higgs-Boson, Gravitational waves are such examples in cosmology, while Vaccines, Covid and incurable diseases are the examples in medicine.

          PS. Religion has important value for many as it connects them with the mysteries of nature and their relationship to it.

          Reply

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