In a recent study submitted to Earth and Planetary Astrophysics, an international team of researchers discuss the various mission design options for reaching a hypothetical Planet 9, also known as "Planet X," which state-of-the-art models currently estimate to possess a semi-major axis of approximately 400 astronomical units (AU). The researchers postulate that sending a spacecraft to Planet 9 could pose scientific benefits much like when NASA's New Horizons spacecraft visited Pluto in 2015. But does Planet 9 actually exist?

"It is hard to put a specific number on the confidence level because so many uncertainties remain," said Dr. Manavsi Lingam, who is an Assistant Professor at the Florida Institute of Technology, and a co-author on the study.

As NASA prepares to usher in a new form of planetary defense, one Johns Hopkins engineer will be eagerly awaiting the big collision that she is helping orchestrate.

Elena Adams, the mission systems engineer at the Johns Hopkins Applied Physics Laboratory, and her team will spend the next two weeks carefully observing Didymos, a double-asteroid system that poses no threat to Earth and yet will be the target of NASA's Double Asteroid Redirection Test—a first-of-its-kind, proof-of-concept mission that will intentionally crash a spacecraft into an asteroid's moonlet to deflect it away from its course.

"During the day of impact, I'll be more of a conductor, making sure that all of the orchestra is following the beat and playing their parts," said Adams, who will discuss the mission during talk in Hodson Hall on the university's Homewood campus on Thursday at 5 p.m.

When NASA's Artemis I mission launches later this year, its crew will include Helga and Zohar, two manikin models designed in collaboration with Duke University.

These models, called "phantoms," are made of materials that mimic human bones, soft tissue and organs, and they'll be fitted with sensors that will measure radiation exposure as they travel to the moon and back. Paul Segars and Ehsan Samei, both researchers at the Carl E. Ravin Advanced Imaging Laboratories at the Duke University School of Medicine, helped develop these phantoms using methods originally created to study how different medical procedures, tools and techniques precisely affect organs throughout the human body.

"Usually these 'phantoms' are virtual, and we use them to create avatars of patients. The goal of our work is that instead of conducting a clinical trial on human patients, you can use these avatars and run a simulated clinical trial through a computer," explains Samei, the Reed and Martha Rice Distinguished Professor of Radiology.