long-period comet that, because of its relatively close passage to Earth, was observed as one the brightest comets of the 20th century. It was discovered on Jan. 30, 1996, by the Japanese amateur astronomer Yuji Hyakutake using large binoculars. Visible to the naked eye in late February of that year, it became spectacular in March, developing a long blue plasma tail and a white dust tail that was much shorter but wider. It finally became five or six times as bright as a first-magnitude star when it passed Earth at a mere 0.1 astronomical unit (AU; 15 million km 【9.3 million miles】) on March 24–25. It faded away in early April and reached perihelion (closest distance to the Sun) at 0.23 AU from the Sun on May 1.