History will be made on Tuesday when Nasa's New Horizons probe sweeps past the icy world known as Ultima Thule. Occurring some 6.5 billion km (4 billion miles) from Earth, the flyby will set a new record for the most distant ever exploration of a Solar System object by a spacecraft.

New Horizons will gather a swathe of images and other data over the course of just a few hours leading up to and beyond the closest approach. This is timed for 05:33 GMT. At that moment, the probe will be about 3,500km from Ultima's surface and moving at 14km/s.

When its observations are complete, the robotic craft will then turn to Earth to report in and begin downlinking the gigabytes of information stored in its memory. Mission scientists, gathered in a control centre at the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, are excited at what lies in prospect.

Virtually nothing is known about this next target for New Horizons, however.

Telescopic measurements indicate it is about 20-30km across, although scientists concede it could actually be two separate entities moving very close to each other, perhaps even touching. The next couple of days will tell.

Signals from the Nasa probe confirm it has survived a flyby of Ultima Thule, the most distant object ever explored in the Solar System.

Scientists at the American space agency confirmed New Horizons was in a "healthy" condition after passing the icy space rock some hours ago.

The probe will send photos and other observations over the coming months.

The earliest images could be made public as soon as Wednesday.

Definitely. I am looking forward to seeing the images.

The image was acquired when the Nasa spacecraft was just 6,700km from its target. Surface details are now much clearer.

New Horizons' data is coming back very slowly, over the next 20 months. This is partly to do with the great distance involved (the separation is 6.5 billion km) but is also limited by the small power output of the probe's transmitter and the size (and availability) of the receive antennas here on Earth. It all makes for glacial bit rates.

The new image was obtained with New Horizons' wide-angle Multicolor Visible Imaging Camera (MVIC) and gives a resolution of 135m per pixel. There is another version of this scene taken at even higher resolution by the probe's Long Range Reconnaissance Imager (LORRI), but this has not yet been downlinked from the probe.