AN astronomer is to give a guided tour of the solar system through the majestic spires of Oxford as part of a drive to help his disabled nephew.

Robert Simpson, a doctor in astrophysics, will guide people from the sun to Neptune on a walk through the city.

It will raise money for an operation for Mr Simpson’s nephew, three-year-old Taliesin Campbell, who suffers from cerebral palsy.

At present Taliesin cannot walk, but it is hoped a £40,000 operation in the United States could improve his life.

Dr Simpson and other supporters has raised £25,000 since January with more than 100 events.

Selective dorsal rhizotomy involves cutting some of the sensory nerve fibers that come from the muscles and enter the spinal cord.

This leads to improvements in sitting, standing, walking, and balance control in walking.

The solar system walk will start at 2pm today from the Bridge of Sighs, New College Lane – close to Edmond Halley’s home, the man who discovered Halley’s Comet.

A one-metre wide globe on the top of the Radcliffe Camera will be used as the sun, and the rest of the journey will be to that scale.

The Earth, to that scale, is the size of a fingernail and sits on the edge of the camera’s square.

High Street will be used to demonstrate the asteroid belt, and Saturn will rest in Christ Church Meadows.

The walk is under two miles and will finish at Neptune, just beyond the Head of the River, St Aldate’s.

Along the way, Dr Simpson, 29, of Springfield Park, Witney, will discuss the solar system, the scale of the planets and how they were discovered.

He said: “We’re raising money to give Tal an operation that will change his life forever. And it’s just a nice way to feel how big the solar system is.

“You will find yourself walking a long way between Saturn and Uranus – you will be amazed at how empty the solar system is. People feel like they’re very close to the sun, but we’re not.”

Dr Simpson hopes to develop the walk and one day install plaques at each of the locations.

It is his latest star-themed event to raise money for his nephew.

For more information about the appeal, visit l Tickets for the walk cost £10 for adults and £5 for children from For more information about the campaign, go online at