Archive – Page 126 – Astronomy Now

Surprisingly rapid magnetic field reversals pose risks to Earth

28 August 2018 Astronomy Now

About 100,000 years ago, Earth’s magnetic field reversed polarity in just two centuries or so, a surprisingly rapid reversal that, if it happened today, could cost trillions in damage to power and communications systems, researchers say.

See bright Comet 21P’s close brush with conspicuous Capella

27 August 2018 Ade Ashford

If you’ve never seen a comet, there’s currently a bright example visible in the late evening about to make a close approach to the 6th brightest star in the night sky on the UK night of 2–3 September. We show you how to find Comet 21P/Giacobini-Zinner around the time it passes within a degree of prominent star Capella.

Meteorite data indicate Jupiter underwent distinct growth phases

27 August 2018 Astronomy Now

Analysis of isotopes in meteorites shows Jupiter underwent distinct growth phases, rapidly accreting small particles to build a core and then slowing as it pulled in larger planetesimals that generated enough heat to slow gas accretion.

The Hubble Space Telescope looks into the heart of M13

26 August 2018 Astronomy Now

The great globular cluster in Hercules, M13, was first noted by western astronomers in 1714 when Edmund Halley described it as a “little patch” that “shews it self to the naked Eye.” The Hubble Space Telescope takes it to another level.

OSIRIS-REx captures its first images of asteroid Bennu

25 August 2018 Astronomy Now

NASA’s OSIRIS-REx spacecraft has captured its first images of asteroid Bennu at a range of 2.2 million kilometres (4.1 million miles); the probe will slip into orbit around Bennu on New Year’s Eve to kick off a sample-return mission

The Milky Way arches over La Silla Observatory

23 August 2018 Astronomy Now

The Milky Way arcs above ESO’s La Silla Observatory in this spectacular panorama demonstrating the extraordinarily clear, dark sky enjoyed by astronomers at one of the premier viewing sites in the world. This image captures the disk of the galaxy, the Large and Small Magellanic Clouds and Jupiter.

See the Moon meet the Red Planet on the UK night of 23 August

23 August 2018 Ade Ashford

Mars may be almost four weeks past opposition, but it’s still an imposing sight low in the southern sky around local midnight. But if you are in any doubt about identifying the Red Planet, the waxing gibbous Moon acts as a convenient celestial guide late into the UK night of Thursday, 23 August. See both the Moon and the Red Planet in the same field of view of low-power binoculars.

See innermost planet Mercury’s favourable dawn show

22 August 2018 Ade Ashford

Mercury attains its maximum westerly elongation from the Sun on 26 August, meaning that the innermost planet is currently well placed for observation from the UK and Western Europe in the eastern sky around 40 minutes before sunrise. In addition to those in the evening sky, you might just see all five bright naked-eye planets this month!

An aurora by any other name? Not if it goes by STEVE

22 August 2018 Astronomy Now

Scientists studying an unusual atmospheric “skyglow” phenomenon known as STEVE events have determined they are not generated by the same processes responsible for more familiar auroral displays.

Ice deposits confirmed near Moon’s poles, confirming earlier indications

21 August 2018 Astronomy Now

Data from a NASA instrument aboard India’s Chandrayaan-1 spacecraft has directly observed ‘definitive’ evidence of ice in shadowed craters at the Moon’s south polar region and with more sparsely distributed ice near the north pole.