Institute of Astronomy

Astronomy News

BepiColombo arrives at Europe's Spaceport

14 May 2018 - 9:07am

The spacecraft of the BepiColombo mission to Mercury have arrived safely at Europe's Spaceport in Kourou, French Guiana, marking the start of six months of preparation to ready the craft for launch.

NASA Hosts Live Discussion about Europa Findings, Potential for Life

14 May 2018 - 9:07am
NASA will host a Science Chat at 1 p.m. EDT Monday, May 14, to discuss the latest analysis of Jupiter’s moon Europa and its status as one of the most promising places in the solar system to search for life.

Mars Helicopter to Fly on NASA’s Next Red Planet Rover Mission

14 May 2018 - 9:06am
NASA is sending a helicopter to Mars. The Mars Helicopter, a small, autonomous rotorcraft, will travel with the agency’s Mars 2020 rover mission, currently scheduled to launch in July 2020, to demonstrate the viability and potential of heavier-than-air vehicles on the Red Planet.

NASA’s NICER Mission Finds an X-ray Pulsar in a Record-fast Orbit

14 May 2018 - 9:06am

Scientists analyzing the first data from the Neutron star Interior Composition Explorer (NICER) mission have found two stars that revolve around each other every 38 minutes — about the time it takes to stream a TV drama. One of the stars in the system, called IGR J17062–6143 (J17062 for short), is a rapidly spinning, superdense star called a pulsar. The discovery bestows the stellar pair with the record for the shortest-known orbital period for a certain class of pulsar binary system.

News Article Type: Homepage ArticlesPublished: Friday, May 11, 2018 - 10:28

NASA Hosts Live Discussion about Europa Findings, Potential for Life

14 May 2018 - 9:06am
Portal origin URL: NASA Hosts Live Discussion about Europa Findings, Potential for LifePortal origin nid: 424281Published: Friday, May 11, 2018 - 10:38Featured (stick to top of list): noPortal text teaser: NASA will host a Science Chat at 1 p.m. EDT Monday, May 14, to discuss the latest analysis of Jupiter’s moon Europa and its status as one of the most promising places in the solar system to search for life.Portal image: A view of Europa created from images taken by NASA's Galileo spacecraft in the late 1990s.Science Categories: Solar System

Black Hole Bounty Captured in the Milky Way Center

11 May 2018 - 9:31am

Astronomers have discovered evidence for thousands of black holes located near the center of our Milky Way galaxy using data from NASA’s Chandra X-ray Observatory.

News Article Type: Homepage ArticlesPublished: Thursday, May 10, 2018 - 12:43

Exiled Asteroid Discovered in Outer Reaches of Solar System

10 May 2018 - 9:25am
An international team of astronomers has used ESO telescopes to investigate a relic of the primordial Solar System. The team found that the unusual Kuiper Belt Object 2004 EW95 is a carbon-rich asteroid, the first of its kind to be confirmed in the cold outer reaches of the Solar System. This curious object likely formed in the asteroid belt between Mars and Jupiter and has been flung billions of kilometres from its origin to its current home in the Kuiper Belt.

NASA Awards Grants for Research into Life in Universe

10 May 2018 - 9:25am
NASA has awarded five-year grants, each approximately $8 million, to three research teams that will study the origins, evolution, distribution and future of life in the universe.

Looking at the Stars

10 May 2018 - 9:25am

Looking at the Stars

Looking at the Stars, Published online: 09 May 2018; doi:10.1038/d41586-018-05101-4

Looking at the Stars

What Is Dark Matter?

10 May 2018 - 9:25am

What Is Dark Matter?

What Is Dark Matter?, Published online: 09 May 2018; doi:10.1038/d41586-018-05096-y

An elusive substance that permeates the universe exerts many detectable gravitational influences yet eludes direct detection.

'Marsquake' monitor due to fly to Mars in Nasa mission

8 May 2018 - 10:03am

Scientists at Imperial College London have spent more than 25 years developing the device.

ESA selects three new mission concepts for study

8 May 2018 - 10:01am

A high-energy survey of the early Universe, an infrared observatory to study the formation of stars, planets and galaxies, and a Venus orbiter are to be considered for ESA's fifth medium class mission in its Cosmic Vision science programme, with a planned launch date in 2032.

An absolute sodium abundance for a cloud-free ‘hot Saturn’ exoplanet

8 May 2018 - 10:01am

An absolute sodium abundance for a cloud-free ‘hot Saturn’ exoplanet

An absolute sodium abundance for a cloud-free ‘hot Saturn’ exoplanet, Published online: 07 May 2018; doi:10.1038/s41586-018-0101-7

The optical transmission spectrum for the ‘hot Saturn’ exoplanet WASP-96b reveals a clear atmosphere, an atmospheric sodium abundance and hence its metallicity, which is consistent with the metallicity trend observed in Solar System planets and exoplanets.

Prof Stephen Hawking's multiverse finale

3 May 2018 - 9:20am

In his last paper, the Cambridge physicist tackles multiple universes and a cosmic paradox.

Hubble detects helium in the atmosphere of an exoplanet for the first time [heic1809]

3 May 2018 - 9:16am

Astronomers using the NASA/ESA Hubble Space Telescope have detected helium in the atmosphere of the exoplanet WASP-107b. This is the first time this element has been detected in the atmosphere of a planet outside the Solar System. The discovery demonstrates the ability to use infrared spectra to study exoplanet extended atmospheres.

New Science from Jupiter

3 May 2018 - 9:14am
Video Length: 4:47

As the Juno spacecraft orbits Jupiter, new discoveries about the giant planet continue to be made.

Read this story

Video Links: New Science from Jupiter - mp4YouTubeVimeo

Taming the multiverse: Stephen Hawking’s final theory about the big bang

3 May 2018 - 9:13am

The theory, which was submitted for publication before Hawking’s death earlier this year, is based on string theory and predicts the universe is finite and far simpler than many current theories about the big bang say.

Professor Hertog, whose work has been supported by the European Research Council, first announced the new theory at a conference at the University of Cambridge in July of last year, organised on the occasion of Professor Hawking’s 75th birthday.

Modern theories of the big bang predict that our local universe came into existence with a brief burst of inflation – in other words, a tiny fraction of a second after the big bang itself, the universe expanded at an exponential rate. It is widely believed, however, that once inflation starts, there are regions where it never stops. It is thought that quantum effects can keep inflation going forever in some regions of the universe so that globally, inflation is eternal. The observable part of our universe would then be just a hospitable pocket universe, a region in which inflation has ended and stars and galaxies formed.

“The usual theory of eternal inflation predicts that globally our universe is like an infinite fractal, with a mosaic of different pocket universes, separated by an inflating ocean,” said Hawking in an interview last autumn. “The local laws of physics and chemistry can differ from one pocket universe to another, which together would form a multiverse. But I have never been a fan of the multiverse. If the scale of different universes in the multiverse is large or infinite the theory can’t be tested. ”

In their new paper, Hawking and Hertog say this account of eternal inflation as a theory of the big bang is wrong. “The problem with the usual account of eternal inflation is that it assumes an existing background universe that evolves according to Einstein’s theory of general relativity and treats the quantum effects as small fluctuations around this,” said Hertog. “However, the dynamics of eternal inflation wipes out the separation between classical and quantum physics. As a consequence, Einstein’s theory breaks down in eternal inflation.”

“We predict that our universe, on the largest scales, is reasonably smooth and globally finite. So it is not a fractal structure,” said Hawking.

The theory of eternal inflation that Hawking and Hertog put forward is based on string theory: a branch of theoretical physics that attempts to reconcile gravity and general relativity with quantum physics, in part by describing the fundamental constituents of the universe as tiny vibrating strings. Their approach uses the string theory concept of holography, which postulates that the universe is a large and complex hologram: physical reality in certain 3D spaces can be mathematically reduced to 2D projections on a surface.

Hawking and Hertog developed a variation of this concept of holography to project out the time dimension in eternal inflation. This enabled them to describe eternal inflation without having to rely on Einstein’ theory. In the new theory, eternal inflation is reduced to a timeless state defined on a spatial surface at the beginning of time.

“When we trace the evolution of our universe backwards in time, at some point we arrive at the threshold of eternal inflation, where our familiar notion of time ceases to have any meaning,” said Hertog.

Hawking’s earlier ‘no boundary theory’ predicted that if you go back in time to the beginning of the universe, the universe shrinks and closes off like a sphere, but this new theory represents a step away from the earlier work. “Now we’re saying that there is a boundary in our past,” said Hertog.

Hertog and Hawking used their new theory to derive more reliable predictions about the global structure of the universe. They predicted the universe that emerges from eternal inflation on the past boundary is finite and far simpler than the infinite fractal structure predicted by the old theory of eternal inflation.

Their results, if confirmed by further work, would have far-reaching implications for the multiverse paradigm. “We are not down to a single, unique universe, but our findings imply a significant reduction of the multiverse, to a much smaller range of possible universes,” said Hawking.

This makes the theory more predictive and testable.

Hertog now plans to study the implications of the new theory on smaller scales that are within reach of our space telescopes. He believes that primordial gravitational waves – ripples in spacetime – generated at the exit from eternal inflation constitute the most promising “smoking gun” to test the model. The expansion of our universe since the beginning means such gravitational waves would have very long wavelengths, outside the range of the current LIGO detectors. But they might be heard by the planned European space-based gravitational wave observatory, LISA, or seen in future experiments measuring the cosmic microwave background.

Reference:
S.W. Hawking and Thomas Hertog. ‘A Smooth Exit from Eternal Inflation?’’ Journal of High-Energy Physics (2018). DOI: 10.1007/JHEP04(2018)147

Professor Stephen Hawking’s final theory on the origin of the universe, which he worked on in collaboration with Professor Thomas Hertog from KU Leuven, has been published today in the Journal of High Energy Physics

We are not down to a single, unique universe, but our findings imply a significant reduction of the multiverse, to a much smaller range of possible universes.Stephen HawkingAndre PattendenStephen Hawking


The text in this work is licensed under a Creative Commons Attribution 4.0 International License. For image use please see separate credits above.

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A New Supernova Over Munich

30 April 2018 - 9:08am
On 26 April 2018, the ESO Supernova Planetarium & Visitor Centre was officially inaugurated, and its doors will be open to the public from tomorrow 28 April 2018. The centre, located at ESO Headquarters in Garching, Germany provides visitors with an immersive experience of astronomy in general, along with ESO-specific scientific results, projects, and technological breakthroughs. All activities in the ESO Supernova will be free of charge during 2018, and shows and other events can be booked online.

Physicists in Earth’s remotest corners race to reproduce ‘cosmic dawn’ signal

30 April 2018 - 9:07am

Physicists in Earth’s remotest corners race to reproduce ‘cosmic dawn’ signal

Physicists in Earth’s remotest corners race to reproduce ‘cosmic dawn’ signal, Published online: 27 April 2018; doi:10.1038/d41586-018-04966-9

Teams rush to capture radiation from Universe’s first stars and to explain puzzling observations.