Earth may have underground ‘ocean’ three times that on surface

After decades of searching scientists have discovered that a vast reservoir of water, enough to fill the Earth’s oceans three times over, may be trapped hundreds of miles beneath the surface, potentially transforming our understanding of how the planet was formed. Full story here

Photo: Blue Line Pictures/Getty Images

A giant rocky planet roughly twice the size of Earth and with nearly 20 times as much mass has been spotted in orbit around a faraway star. The planet is the first to be classed as a “mega-Earth” – an alien world that dwarfs the other rocky planets known to exist outside the solar system. More on this story

Illustration: CfA/David A Aguilar

breakingnews:

‘Baby picture’ of the universe unveiled

NBC News: The European-led team behind the Planck cosmology probe on Thursday released the mission’s first all-sky map of the cosmic microwave background — a “baby picture” of the universe that could eventually reveal how it inflated in the first moments of its existence, and whether it possesses the extra dimensions that are predicted by some theorists.

“To a cosmologist, this map is a gold mine of information,” University of Cambridge astrophysicist George Efstathiou, a member of the Planck science team, said during a Paris news conference. He joked that not that long ago, cosmologists might have “given up their children” to have such a map in their hands.

Photo: The Planck cosmology probe has produced the most detailed all-sky map to date showing the cosmic background radiation, also known as the afterglow of the big bang. (ESA)

As a commenter on our story on Guardian Science said:

DoctorChris

A fantastic achievement. But is it exciting or depressing that 95% of the Universe is made up of stuff we know nothing about?

You can also see a big big version of the picture on our site here.

What causes sinkholes?

It’s the stuff of nightmares: last week, the ground opened up and swallowed a Florida man as he lay sleeping in his home. But why do these sinkholes occur and how widespread are they?

Photos: 1. Three buildings collapsed after a huge hole appeared in, Guangzhou, Guangdong province, China on 28 Jan 2013. There are no casualties from the incident, which was near a metro tunnel construction site. Imaginechina/Rex Features. 2. Guatemala city, 2007 Photograph: Ulises Rodriguez/EPA/Corbis

When veteran explorer Sir Ranulph Fiennes is in the depths of a six-month trip – which will expose him to temperatures of -90C and long nights of darkness that will test human endurance to its limit – you can be sure he’ll welcome any warm message to keep his spirits high. 

With the expedition ship due to set sail from Cape Town on Monday and reach their Antarctic dock in the coming weeks, we want Fiennes and his team to take with them messages from proud Brits, fans and well-wishers to spur them on in the cold dark nights which lie ahead. 

Here’s a picture of the Guardian’s head of environment Damian Carrington with his message…

Click on this link to find out how you can post yours

The planet Earth is black! Nasa lights up the world at night

Space agency satellite uses hi-res visible and infrared imager powerful enough to spot a single ship’s light to produce ‘black marble’ cloud-free night-time pictures - see them in this stunning blog.

Photo: NASA EO/Rex Features

Photograph: VIIRS/Suomi-NPP/NASA

A gallery of satellite images of the earth in June 2012:

There have been many images of the full disc of Earth from space – a view often referred to as ‘the Blue Marble’ – but few have looked quite like this. Using natural-colour images from the visible/infrared imaging radiometre suite (VIIRS) on the recently launched Suomi-NPP satellite, a Nasa scientist has compiled a new view showing the Arctic and high latitudes

Next week, 20 years after the Earth summit in Rio de Janeiro, politicians, businesses, activists, NGOs and more will meet again for Rio+20. The UN describes the conference as “a historic opportunity to define pathways to a safer, more equitable, cleaner, greener and more prosperous world for all”. What does this mean to you? What message do you want to send to the summit?

Steven Opio in Uganda, with his message to the Rio+20 summit. Photograph: Ben Parkinson

Photograph: NASA

This image shows ocean surface currents around the world during the period from June 2005 to December 2007. See more satellite images of the earth in our gallery.

Photo

Photograph: Aqua/NASA

The colours of a changing autumn landscape across western Europe on 1 October 2011 on a sunny afternoon. In some areas across the region, the dark greens of summer forest are gently softened by pale greens and yellows of senescent leaves of deciduous trees. In the south, the Alps are covered by a coating of snow.

For more images captured by European Space Agency and Nasa satellites last month, click here.