Exploring the Effects of Impacts onto Phaethon and Other Near Earth Asteroids

双子座流星雨的罕见之处在于，它的母体3200法厄同是一颗小行星，而不是彗星。大多数流星雨是由彗星通过太阳加热和蒸发排出的粒子产生的。在法厄同的例子中，机制就不那么明显了。该团队之前解释说，101955 Bennu的质量损失是由于彗星粒子的微流星体撞击造成的。该团队现在将使用NASA的气象工程模型（MEM）为Phaethon建模。他们的假设是，双子座流星雨是由微陨石撞击形成的，导致法厄同留下了一串粒子，很像彗星。该小组还将对靠近太阳的弱束缚原始天体的质量损失和进化进行建模。该团队还将参加SwRI的暑期科学项目（SSP），并为参加该项目的高中生开展为期两天的计算课程。该团队将使用美国宇航局的流星体工程模型来模拟微流星体对一个弱原始表面的影响，该表面被认为代表3200 Phaethon，位于距离太阳0.14天文单位的区域。在先前与MEM的合作中，研究小组发现毫米大小的流星体以40公里/秒的速度撞击Bennu的频率足以解释所有粒子喷射事件的限制。利用Bennu的研究来指导他们的工作，该团队将(i)使用MEM模型来确定法厄同每次通过近日点时喷出的碎片的质量/方向，（ii）使用动力学模型来确定法厄同碎片是否可以在过去的1000年里重现双子座，（iii）使用动力学模型来探索法厄同的起源，他们认为它可能不是来自Pallas小行星家族。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The Geminid Meteor Shower is rare in that its parent body, 3200 Phaethon, is an asteroid, not a comet. Most meteor showers are generated by particles expelled from comets by solar heating and evaporation. In Phaethon’s case, the mechanism is less obvious. The team previously explained mass loss at 101955 Bennu as arising due to micrometeoroid impacts from comet particles. The team will now model this idea for Phaethon using NASA’s Meteoriod Engineering Model (MEM). Their hypothesis is that the Geminids are formed through micrometeorite impacts, causing Phaethon to leave a trail of particles, much like a comet. The team will also model mass loss and evolution for weakly-bound primitive bodies that pass close to the Sun. The team will also participate in SwRI’s Summer Science Program (SSP) and conduct a two-day computational session for high-school students in the program.The team will use NASA’s Meteoroid Engineering Model to model micrometeoroid impact on a weak primitive surface as is thought to represent 3200 Phaethon in a region at 0.14 AU from the Sun. In prior work with MEM, the team found mm-sized meteoroids strike Bennu frequently enough at 40 km/s to explain all particle ejection event constraints. Using the Bennu study to guide their work, the team will (i) use the MEM model to determine the mass/direction of ejected debris from Phaethon per perihelion passage, (ii) use dynamical models to determine whether Phaethon debris can reproduce the Geminids over the last ~1000 years, and (iii) use dynamical models to explore Phaethon’s origin, which they argue is probably not from the Pallas asteroid family.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.