On Friday night, a new tool will be used to fight crime in Inwood Hill Park: a $12,000 telescope. Following a string of sexual assaults in the area, the urban astronomer Jason Kendall will mix stargazing with discussions on community safety in what he's calling “Take Back the Park” nights.

“The park is there for the community. It’s our park,” said Kendall, adding that he did not want Inwood to cede the park to drug dealers, prostitutes, or criminals. “You got to use the park or lose it.”

Kendall rebranded his sky-watching tours as Take Back the Park nights after a 28-year-old woman was sexually assaulted in the park near the ballfields where he sets up his six-foot-tall telescope. The assault was one of three attacks in the neighborhood on June 10 and 11.

The astronomer said a telescope puts most anyone at ease, including a group of tattooed men in muscle shirts he recently encountered in the park late at night.

"All of a sudden they go, 'Wow, this is really cool,' and they call up a bunch of people and go, 'That's Saturn, I've never seen the rings before,'" he said.

Kendall's first "Take Back the Park" event last week drew about 100 people — a cross-section of the neighborhood that included more women than had been attending. Theater professional Clara Barton Green talked to the dozen or so teens and men and women in their 20s, 30s and 40s, some of whom were examining Saturn and the moon last week.

"I talked a lot about women's safety, how to protect yourself, but also not to live in fear," Green said. "I think that that's a really important principle."

The actor, director and producer was sexually assaulted several years ago but was able to fight off her attacker.

Inwood residents said that the New York City Department of Parks and Recreation and the police have stepped up enforcement since the June 10 attack in the park, though the suspect is still at large. Parks Enforcement Patrol (P.E.P.) officers, who are unarmed "quality of life" officers who keep the peace, give directions, and help sick people, have also been seen in the park. A parks department spokeswoman said crime was a policing issue but that P.E.P.s help with community morale.

“If people see a uniform, they feel more comfortable,” she said.

Residents said they had seen more foot and car patrols in the park and that a mobile unit has been stationed near the southern end of the park.

The New York Police Department did not respond to calls and emails for comment on extra policing measures.

The next "Take Back the Park" night is scheduled to be held this Friday from 8:30 to 11 P.M.