On August 27, Mars -- the fourth planet from the Sun -- will shine red and orange and as bright as Jupiter, the giant of our solar system.
"Telescope sales are 1.7 times to twice as large as the previous year," said a spokesman for Bic Camera, which operates 20 electronics goods stores across the nation.
"Customers range from middle-aged men to students who plan to watch the event with their families," he said, declining to give specific sales figures.
Mars is now at its closest to Earth since Neanderthals walked our planet.
On August 27, the Red Planet will be 55.76 million kilometresmillion miles) from Earth, according to Belgian astronomer Jean Meeus, who says the two planets last came as close nearly 60,000 years ago.
Watanabe Kyogu, a globe manufacturer based in Soka City north of Tokyo, has sold 250 Mars globes in the first seven months of this year.
"The figure is quite big as we sell only about 50 (Mars) globes in normal years, mainly to schools," a company official said, adding orders continued to flood in this month.
Mars globes sold by the company are priced from 13,000 yen (110 dollars) to 500,000 yen.
Loft, a miscellaneous goods store operator, has been overwhelmed by strong demand for telescopes after it started sales in early May.
"Telescopes soon sold out... the main customers were fathers with small children," a Loft spokeswoman said.
Hankyu Travel in early July started offering package tours to Arizona for amateur astronomers, drawing 1,200 enquiries over the Internet.
Seventeen people are to leave Tokyo on Saturday for an eight-day trip, priced at 298,000 yen (2,500 dollars), accompanied by a professional astronomer.
They will visit Lowell Observatory, located in Flagstaff, Arizona, at 7,260 feet (2,180 metres) above sea level. The Japanese group has reserved a telescope there for the celestial show.
The privately owned observatory is best known for the discovery of Pluto.
The next time the two planets will be closer than in 2003 will be in 2287.