The Chinese space agency could land its first astronauts on the moon within a decade in a move that would mark the beginning of a new age of lunar exploration, experts said today.

The decision by the Obama administration to scrap Nasa's plans to return to the moon leave China well placed to become the second nation to land humans on the lunar surface. "The moon is an obvious target for China and they could be there in 2020," said Ken Pounds, professor of space science at Leicester University.

The US president's budget proposal, unveiled on Monday, lacked the funds to sustain Nasa's $81bn Constellation programme, the spaceships and rockets designed to put humans back on the moon by 2020. But the decision to scrap Nasa's plans for a permanent return has left the door open for other countries.

China has lifted astronauts into orbit and sent its first robotic missions to the moon. India found water on the surface with its first lunar mission last year, and plans to launch astronauts into Earth orbit in 2016. Japan, too, has sent a satellite to the moon, returning extraordinary HDTV video of the surface.

With the US space agency out of the running, the leading contender for a return to the moon is China. In 2004, government officials announced an unmanned lunar exploration programme that would put satellites in lunar orbit, touch down on the surface and finally bring home up to two kilograms of rock samples before 2020.

The second probe in the programme is expected to launch in October this year. It will scan the surface of the moon from an altitude of 60 miles and look for suitable landing sites for future missions.

The Chinese human spaceflight programme has progressed at speed on $2bn a year, roughly one tenth of the budget Nasa receives. After only four unmanned test flights, the first Chinese astronaut flew in Earth orbit in 2003. Five years later, China became only the third country to complete a spacewalk, paving the way for work on a space station.

Since then the Chinese space programme has grown to include plans to launch three space stations between 2011 and 2015 and, if funding permits, to send a crewed mission to the moon, perhaps as early as 2022. Development of the first Chinese lunar rover is under way and it is scheduled to launch on a three-month mission to the lunar equator in 2013.

Experts are waiting to see how the Chinese space agency reacts to Obama's plans for Nasa.

"China might rub their hands and think this is their chance to head for the moon, or they might see that the pressure is off and not rush things," said Pounds.

The former chief administrator at Nasa, Michael Griffin, has already criticised Obama's plans as an admission that Nasa will not be a significant player in human space flight for the foreseeable future.

Giving testimony to the Senate in 2007, he said it was likely that "China will be able to put people on the moon before we will be able to get back". He added: "I admire what they have done, but I am concerned that it will leave the United States in its wake." Pounds said: "The Americans are the only ones who can say 'we've been there, done that,' but the point is they are not there now.

"The moon is very visible and any proposition by another country to set up a permanent presence there would be unacceptable to the Americans."

A crewed mission to the moon in the 21st century will be a different beast from the Apollo programme. The blurred images would be replaced by colour HDTV footage. The communications would be clear and frequent. From a permanent base, astronauts would truly explore the moon instead of only scratching the surface. The venture could be commercial and scientific in ways that were not possible 40 years ago.

"The pictures from Apollo wouldn't compare with what we might get from Chinese rovers on the surface," said Pounds. "The Obama administration has made the decision as if they are the only ones doing human spaceflight. If they were, it might make sense to go on to an asteroid or one of the moons of Jupiter, but they're not. The moon is going to be a target for other countries and having a presence there is going to be a political issue."

Space races

• China was the third country to launch its own manned space missions in 2003 and is now talking of a space station by 2020. Beijing is also in early stages of planning a lunar mission.

• India began satellite missions to the moon in 2008 and plans to send its own astronauts into space by 2016. Rakesh Sharma became the first Indian in orbit in 1984 on a Soviet mission.

• Russia will taxi US astronauts to the international space station when the space ­shuttle programme ends. It plans a mission to Mars, but going to the moon seems a lower priority.

• The European Space Agency concentrates on partnership in the international space station and at present has an eight strong astronauts corps. It has recently – but before Obama's announcement – talked about grabbing a seat on someone else's moon mission.

• Brazil is behind in the space race but is hoping to relaunch an unmannned programme that has been on hold since a launchpad disaster killed 21 people in 2003. It also plans a new generation of satellites to monitor agriculture, territory, deforestation and mineral rescources.