The asteroid has been named 2012 BX34 and is estimated to be about 11m (36ft) in diameter. Though it won't be visible to the naked eye, keen amateur astronomers still have a good chance of sighting it.

Fortunately it's very rare for large asteroids to strike the Earth - perhaps 60 objects greater than 5 km across have done so in the last 600 million years (or an average of about one every 10 million years). One of the most famous was of course the 10km-wide asteroid that may have led to the extinction of the dinosaurs 65 million years ago.

Smaller objects hit our planet more frequently - about 500 football-sized rocks strike the Earth each year.

Find out more about asteroids:

• Astronomy FAQs - will an asteroid hit the Earth?
  
• Fact file - The Minor Planets
  
• Fact file - Near-Earth Asteroids
  
• Impact: Collisions and Catastrophes (past exhibition)

25 January 2012 - A stronger-than-average solar flare at 03:59 GMT on Monday set off a coronal mass ejection travelling at 1400 km/s and reaching Earth yesterday afternoon. Its effects are likely to continue throughout today (Wednesday 25 Jan).

Solar flares are enormous explosions caused by the sudden release of energy from the magnetic fields of sunspots - temporary areas of intense magnetic activity in the Sun's atmosphere (corona). Solar flares in turn can result in coronal mass ejections (CMEs) - huge clouds of high-energy particles blasted into space by a solar flare. These clouds of material can strike the Earth causing geomagnetic storms and triggering a range of phenomena. Some of these are beautiful like the aurora, but others can be disastrous - disrupting satellites and communications systems.

Monday's solar flare triggered the strongest stream of protons seen since 2005. However, scientists predict that the current CME will only cause a minor geomagnetic storm without any visible effects on the ground nor any serious effects on satellites, phone networks or power grids.

Get involved - You can help spot and track solar storms at Solar Stormwatch, a joint web project of the Royal Observatory Greenwich, Zooniverse and Rutherford Appleton Laboratory. If you get involved your work will help give astronauts an early warning if dangerous solar radiation is headed their way - and you could make a new scientific discovery.

The Astronomy Photographer of the Year competition is back! Now in its fourth year, the competition continues to showcase incredible images from amateur astrophotographers all around the world, featuring beautiful objects from within our solar system and far into deep space.

Anyone can enter - whether you're new to astrophotography or a seasoned amateur, and whatever your age. We've had a huge range of images in previous years, from amazing landscape photography that captures the Moon and the Sun to stunning deep space images taken by robotic telescopes. Find out how to enter and what you could win.

Overall winner 2011: Jupiter with lo and Ganymede,
September 2010 by Damian Peach (UK)

The four main competition categories are Earth and Space, Our Solar System, Deep Space and Young Astronomy Photographer of the Year. The judges will also be awarding three additional special prizes: People and Space, Best Newcomer, and Robotic Scope Image of the Year. Find out more about the categories and prizes.

Entries to the competition close at midday (BST) on Friday 29 June 2012.

The winning images will be displayed at the Royal Observatory Greenwich from September in the free Astronomy Photographer of the Year exhibition. There's still time to see the winning images from 2011 (closes 12 February).

Good luck, and we look forward to seeing your photos in Astronomy Photographer of the Year 2012!

The first meteor shower of the year is underway and peaking at the moment. The Quadrantids is one of the most spectacular but brief showers of the year, at its peak producing 60-120 meteors per hour.

Meteors, popularly known as 'shooting stars', appear as fleeting streaks of light and most are caused by particles no bigger than grains of sand. These collide with the Earth's atmosphere at up to 70 km per second (157,000 mph) and burn up. With patience, meteors can be seen on any night of the year.

The Quadrantids

All the meteors in the Quatrandid shower appear to come from the same point in the sky, or radiant, situated near the familiar grouping of the Plough. The shower is named for the former constellation Quadrans Muralis, the stars of which once lay in that direction. The Quadrantids are less well-known than many other meteor showers, probably because only the hardiest observers brave the cold January nights.

In contrast with many meteor showers, the Quadrantids are not obviously connected to a particular modern-day comet but some astronomers believe them to originate from a large cometary body that broke up thousands of years ago.

In 2003, SETI institute astronomer Peter Jenniskens suggested that the Quadrantids are tied to the near-Earth asteroid 2003EH1 (see Dr Jenniskens' paper here). Dr Jenniskens believes this object is actually an extinct comet, possibly once seen by the Chinese 500 years ago in 1490. The comet may have subsequently broken up, releasing all its volatile material in a single event. When the Earth passes through the dust cloud each January we see the meteor shower.

Viewing meteors

Unlike many astronomical objects, observers need no special equipment to view meteors. The sensitivity and wide field of view of the human eye are perfect for watching the Quadrantids and all observers need to do is watch the sky for a few minutes. 

As ever, it pays to leave the lights of the city behind and rural sites will offer the best view of the Quadrantids, but (weather permitting) they should be clearly visible all over the UK. 

The next major meteor shower of the year will be the Lyrids, which peak around 22 April. Find out more about annual meteor showers in our fact file.

Image: Meteors in the Quadrantid shower in January 1995. The image superimposed many video frames to illustrate the apparent origin of the meteors from their radiant. Credit: Sirko Molau, IMO, Archenhold-Sternwarte, NASA.

It should come as no surprise that a 17th-century astronomer was capable of drawing up an astrological chart. Although astronomy and astrology are now very different things, in the early modern period they were still closely allied. In this context it can be useful to think of astronomy as the observational practice that supplied data for a number of purposes, chiefly navigation, surveying, timekeeping and astrology. Flamsteed, like many other early modern astronomers, supplied his data to astrologers and evidently knew well how to cast and interpret a horoscope himself. 

*Times are BST not GMT, and may not correspond exactly with the official (religious) sighting of the crescent moon.

The dates of Ramadan and other Islamic months depend on the sighting of the new crescent Moon.

Information on the visibility of the Moon from anywhere in the world is available from HM Nautical Almanac Office's Websurf facilty:

• - accept the conditions of use (Websurf homepage)
• - select the 'Moon-Viz' link
• - choose or search for a place
• - select a date range
• - The visibility information (time) is in the 'BEST TIME' column; Moon set time is in the 'Moon set' column. NB add +1 hour for BST.
   

Also of interest

• - Al Hijra and the Islamic Calendar - fact file
• - Persian astrolabe - a beautiful astrolabe dating from 1070AH by the Islamic calendar, and including a grid for finding the direction of Mecca from a number of different towns and cities.
• - Arabic (Islamic) brass globe - 18th-century globe showing all 48 constellations that were known to the Ancient Greeks, and engraved with the Arabic names of some of the stars.
• - Transmission of knowledge - as Islam spread across Northern Africa from the 7th century, it helped change the purpose of astronomy: for example, it was now needed to produce accurate tables of prayer times.
   

Artist and blacksmith Matthew Luck Galpin's 'Anvilled Stars' are meteorites that have been heated, hammered, ground and polished into mirrored works of art. The meteorites used to create 'Anvilled Stars' are thought to be more than 4.5 billion years old, and they started out as part of the asteroid belt during the early life of the Solar System. They reached Earth between 4000-6000 years ago after a journey lasting millions of years; they shattered as they entered the atmosphere and crashed into the northern Argentinian desert, witnessed by the local people. The place where they landed is now called Campo del Cielo - the Field of Heaven.

Meteorites are pieces of rock and metal that have fallen from space, providing some of the only physical evidence we have to study the formation of the Solar System. Mirrors are significant not only because they reflect us and our world, but also as the essential components of instruments such as telescopes that we use to study the Universe. By bringing the two together Matthew's work is a creative response in relation to the Universe and our place in it. Matthew says of the artwork: "by working these iron meteorites and mirroring their trajectory, I feel closer to belonging to their journey through space and time, reaching a point of reflection of our part in it all".

Each mirror is unique, and their irregular shapes and cloudy impurities are a joint product of their ancient origins and their transformation into manufactured objects in Matthew's workshop. The six mirrors form an imaginary 'constellation' across the Observatory site and it's up to visitors to locate them all. Five more of Matthew's mirrors are currently on display at the Science Museum in South Kensington, forming a larger constellation of eleven Anvilled Stars spanning London - just the latest chapter in their continuing 4.5-billion year story.

Impact: Collisions & Catastrophes

The Impact exhibition (open at the Royal Observatory until 29 August) takes a look at the fiery debris that bombards earth from space, sometimes laying waste to vast areas and even triggering mass extinctions of plants and animals. It also explores the vital clues that asteroids and meteorites provide about the violent formation of the Solar System.

Now the Royal Observatory is also home to OMEGA's London 2012 Countdown Clock. Installed on the Prime Meridian Line by OMEGA, the Official Timekeeper of the Games, the clock will tick away the seconds, minutes, hours and days until the start of the London 2012 Olympic Games - some of which will be hosted in Greenwich Park.

The clock was unveiled yesterday (27 July 2011) in time to celebrate 'One Year to Go' to the start of the Games.

Conserving the H3 Timekeeper part 6 from Royal Observatory Greenwich on Vimeo.

Conserving the H3 Timekeeper part 5 from Royal Observatory Greenwich on Vimeo.

Conserving the H3 Timekeeper part 4 from Royal Observatory Greenwich on Vimeo.

The timekeeper is now completely dismantled, but the job is not over yet for Jonathan. The case is keeping him busy and presenting surprises as well.

Conserving the H3 Timekeeper part 3 from Royal Observatory Greenwich on Vimeo.

With H3 almost completely dismantled, Jonathan Betts reflects on his progress so far and how the project affected the last man to undertake the task.

Tour 2: 13.00: Charting Greenwich Mean Time
Come to the Prime Meridian of the World and explore the collections at the Royal Observatory, Greenwich with Rory McEvoy, Curator of Horology. Discover how Greenwich Mean Time was determined and kept throughout the years and why an observatory should be so closely connected with precision timekeeping. The tour will include a rare opportunity to see some unusual time related objects from the Museum's reserve collection

Meeting place for tours: Shepherd's Gate Clock, main gate, Royal Observatory. Tours start promptly. Please arrive at least 5 minutes before start.