Maximilian Hamm

• Dr. rer. nat
• PostDoc Position at Freie Universität Berlin

We carry out a numerical study on the thermal behaviour of asteroid 3200 Phaethon, the parent body of the Geminid meteor shower. Phaethon’s orbit is highly eccentric, with the perihelion distance as small as 0.14 au. During the perihelion passage the surface temperature rises so much that the reaction force of the thermal radiation from its surface...

Plain Language Summary The Japanese Hayabusa2 space mission returned samples from asteroid Ryugu. Here we compare the spectra of the sample observed in the middle infrared (5–25 μm) with in‐situ observations in the part of the electromagnetic spectrum. We find differences between the spectra that can be explained by the presence of fine particles o...

The Hayabusa2 mission provided a unique data set of asteroid Ryugu that covers a wide range of spatial scale from the orbiter remote sensing instruments to the returned samples. The MASCOT lander that was delivered onto the surface of Ryugu aimed to provide context for these data sets by producing in situ data collected by a camera (MasCam), a radi...

Sample return provides us with “ground truth” about the visited body, verifying and validating conclusions that can be drawn by remote sensing (both Earth-based and by spacecraft) and via landed instruments on other bodies. The detailed investigation of the mineralogy and geochemistry of Ryugu plays a fundamental role in the understanding of its fo...

In 2022 JAXA issued an Announcement of Opportunity (AO) for receiving Hayabusa2 samples returned to Earth. We responded to the AO submitting a proposal based on using a multi-prong approach to achieve two main goals. The first goal is to address the subdued contrast of remote-sensing observations compared to measurements performed under laboratory...

Context. After landing on C-type asteroid Ryugu, MASCOT imaged brightly colored, submillimeter-sized inclusions in a small rock. Hayabusa2 successfully returned a sample of small particles from the surface of Ryugu, but none of these appear to harbor such inclusions. The samples are considered representative of Ryugu. Aims. To understand the appare...

Sensitive laboratory instruments on Earth are capable of determining the chemical, isotopic, mineralogical, structural, and physical properties of extraterrestrial samples from the macroscopic level down to the atomic scale, allowing to determine the origin and history of the material and answer questions far beyond the reach of current robotic tec...

We present a numerical method for simulating a disk-resolved thermal image of an asteroid with small-scale roughness. In our method, we carry out numerical thermal evolution model of a small but rough area taking into account its latitude, shadowing effect, and re-absorption of the thermal radiation by neighbor. By visualization of the resulting te...

The Near-Earth Asteroid (162173) Ryugu has been investigated by the JAXA Hayabusa2 mission. Hayabusa2 successfully returned samples from two sites of Ryugu’s surface to Earth in December 2020. Part of this mission was the deployment of the MASCOT lander which studied Ryugu’s surface in detail. Ryugu is a rubble-pile asteroid covered in boulders and...

The near-Earth asteroid (162173) Ryugu, the target of Hayabusa2 space mission, was observed via both orbiter and the lander instruments. The infrared radiometer on the MASCOT lander (MARA) is the only instrument providing spectrally resolved mid-infrared (MIR) data, which is crucial for establishing a link between the asteroid material and meteorit...

The Lunar Prospector discovery of areas of neutron suppression and the subsequent interpretation of hydrogen enrichment near the lunar poles brought the possibility of volatile resources sequestered at the poles to the forefront of the lunar science community. Subsequently the LCROSS experiment showed that water ice is present within at least one p...

Intuitive Machines Mission - 2 (IM2) Nova-C lander is slated to land on the Spudis crater side of the Shackleton – de Gerlache connecting ridge (89.5°S, 222.0°E) in late 2022 or early 2023. The Nova-C carries three core payload elements: the NASA-funded Polar Resources Ice-Mining Experiment-1 (PRIME-1), a 4G/LTE communications network developed by...

The JAXA MMX sample return mission to the martian moons will deliver a rover to the surface of Phobos that will investigate the landing area using its navigation cameras (NavCams), its regolith facing cameras (WheelCams), its Raman spectrometer (RAX), as well as its mid infrared radiometer (miniRAD). The distance that can be travelled by the Rover...

Context. After landing on C-type asteroid Ryugu, MASCOT imaged brightly colored, submillimeter-sized inclusions in a small rock. Hayabusa2 successfully returned a sample of small particles from the surface of Ryugu, but none of these appear to harbor such inclusions. The samples are considered representative of Ryugu. Aims. To understand the appare...

Planetesimals—the initial stage of the planetary formation process—are considered to be initially very porous aggregates of dusts1,2, and subsequent thermal and compaction processes reduce their porosity3. The Hayabusa2 spacecraft found that boulders on the surface of asteroid (162173) Ryugu have an average porosity of 30–50% (refs. 4–6), higher th...

In June 2018, after 4 years of cruise, the Japanese space probe Hayabusa2 [1-Watanabe S. et al.: Hayabusa2 Mission Overview. (2017)] reached the Near-Earth Asteroid (162173) Ryugu. Hayabusa2 carried a small Lander named MASCOT (Mobile Asteroid Surface Scout) [2-Ho T. M. et al.: MASCOT-The Mobile Asteroid Surface Scout on-board the Hayabusa2 mission...

At 01:57:20 UTC on October 3rd, 2018, after 3½ years of cruise aboard the JAXA spacecraft HAYABUSA2 and about 3 months in the vicinity of its target, the MASCOT lander was separated successfully by from an altitude of 41 m. After a free-fall of only ~5m51s MASCOT made first contact with C-type near-Earth and potentially hazardous asteroid (162173)...

In this paper, we summarize the findings and deductions for small asteroid Ryugu from Hayabusa-2 remote sensing as well as from MASCOT radiometer (MARA) data. Observations cover the VIS (broadband) and MIR (broadband) wavelength ranges. For a typical rock on Ryugu's surface, we find a thermal inertia of 295±18 Jm-2K-1s-1/2 (Hamm+ 2020), a microporo...

After 3.5 years of cruise, and about 3 months in the vicinity of its target, the MASCOT lander was deployed successfully on 3rd October 2018 by the Hayabusa2 spacecraft onto the C-type near-Earth asteroid (162173) Ryugu. After a free-fall of 5 min 51 sec from an altitude of 41 m MASCOT experienced its first contact with the asteroid hitting a big b...

Lunar surface temperature variations provide key information about the thermophysical properties of the regolith. To date, temperatures have been measured using telescopes and orbiter instruments, providing information from mid-to long infrared (IR) wavelengths. Here we report on temperature measurements in the short wavelength IR at centimeter sca...

Thermophysical properties of the surface of asteroid 162173 Ryugu have been investigated through global, local and close-up thermal imaging from the Hayabusa2 spacecraft using the thermal infrared imager TIR, a two-dimensional thermographic camera. The set of thermal images during one rotation of asteroid allowed to map thermal inertia of the aster...

Both observations of C-type near-Earth asteroids and laboratory investigations of carbonaceous chondritic meteorites provide strong evidence for a high microporosity of C-type asteroids. Boulder microporosity values derived from in-situ measurements at the surface of the rubble-pile NEA (162173) Ryugu are as high as 55 %, which is substantially hig...

Deriving thermophysical properties such as thermal inertia from thermal infrared observations provides useful insights into the structure of the surface material on planetary bodies. The estimation of these properties is usually done by fitting temperature variations calculated by thermophysical models to infrared observations. For multiple free mo...

Deriving thermophysical properties such as thermal inertia from thermal infrared observations provides useful insights into the structure of the surface material on planetary bodies. The estimation of these properties is usually done by fitting temperature variations calculated by thermophysical models to infrared observations. For multiple free mo...

Carbonaceous (C-type) asteroids¹ are relics of the early Solar System that have preserved primitive materials since their formation approximately 4.6 billion years ago. They are probably analogues of carbonaceous chondrites2,3 and are essential for understanding planetary formation processes. However, their physical properties remain poorly known b...

Abstract We have investigated the influence of thin thermally opaque dust layers on the thermal emission of rocks and regolith and determined the thermal response of these dust-covered surfaces to diurnal insolation cycles. Results are computed for Hayabusa2’s target asteroid (162173) Ryugu, which was observed by thermal infrared instruments on the...

JAXA’s Hayabusa2 mission was launched in December 2014 to explore the pristine C-type asteroid (162173) Ryugu, whose bulk material can be considered representative for the volatile rich building blocks that formed the terrestrial planets. C-types are the most common variety of asteroids, and 75% of all known asteroids are of this type. They mainly...

After its release and a descent and bouncing phase, the Hayabusa2 lander MASCOT came to a final rest and MASCOT's cameraMASCam acquired a set of images of the surface of Ryugu. With MASCam's instantaneous field of view of about 1 mrad, the imagesprovide pixel scales from 0.2 to 0.5 mm/pixel in the foreground and up to 1 cm/pixel for surface parts i...

Images from the Optical Navigation Camera system (ONC) onboard the Hayabusa2 spacecraft show the MASCOT lander during its descent to the surface of asteroid (162173) Ryugu. We used results from a previous stereo-photogrammetric analysis that provided precise ONC image orientation data (camera position and pointing), ONC orthoimages, and an ONC-base...

Observations of the C-type NEA(162173) Ryugu by Hayabusa II demonstrated that this asteroid is a low-density rubble pile whose surface is dominated by large boulders. MASCOT’s[1] measurements during its operational phase on the surface of the rubble pile NEA (162173) Ryugu proided boulder brightness temperatures that allowed estimating thermal iner...

Introduction: The Hayabusa2 spacecraft is surveying asteroid Ryugu from June 2018. Global observation by thermal infrared imager TIR revealed low thermal inertia around 200-300J m-2 K-1 s-0.5 [1]. The expected grain size from this thermal inertia was several centimeters [2]. However, the surface of Ryugu is globally filled with larger boulders [3]....

C-type asteroids are among the most pristine objects in the Solar System, but little is known about their interior structure and surface properties. Telescopic thermal infrared observations have so far been interpreted in terms of a regolith-covered surface with low thermal conductivity and particle sizes in the centimetre range. This includes obse...

The measurents of the MASCOT Radiometer MARA are revisited and a detailed thermal model of the MASCOT environment is presented.

The evolution of the temperature and porosity in potential parent bodies of Ryugu was calculated and compared with the measurements of MASCOT and properties of CI and CM chondrites. Key properties of the parent body were estimated.

On October 3rd, 2018 the Hayabusa2 spacecraft [1] delivered the MASCOT lander [2]to the surface of near Earth asteroid (162173) Ryugu,where it operated for 17 hours and 7 min. Ryugu has adiameter of 850-880 m, a geometric geometricalbedo between 0.045 ±0.002 at 0.55 μm and is classified as a Cbtaxonomic type[3]. During the surface mission, MASCOT i...

We investigated whether the MASCOT/MARA thermal radiometer can be used to determine regolith particle size and porosity on the asteroid Ryugu in the Hayabusa2 mission. We used a one-dimensional heat flow model and our own thermal conductivity model for regolith to compare MARA's performance and the expected Ryugu surface temperatures of various par...

The Hayabusa2 sample-return mis-sion [1] reached the Near-Earth Asteroid (162173) Ryugu anddeployedthe MASCOT lander [2],which carriedthe MARA infrared radiometer [3].MARA measured brightness temperaturesof a single boulder for a full diurnal cycle, and the thermal inertia of this boulder was estimated to be 247-375 JK−1m−2s−1/2[4].Whilethis value...

On October 3rd, 2018 the Haya-busa2 spacecraft [1] delivered the MASCOT lander [2] to the surface of near Earth asteroid (162173) Ryugu, where itoperated for 17hoursand 7 min.Ryugu has a diameter of 850-880 m, a geometric V-band geometric albedo between 0.042 and 0.055, a bond albedo of 0.019±0.003, and is classified as a Cg taxonomic type[3]. Duri...

Images from the Optical Navigation Camera system (ONC) onboard the Hayabusa2 spacecraft show the MASCOT lander during its descentto the surface of asteroid (162173) Ryugu. We used results from a previous stereo-photogrammetric analysis that provided precise ONC imageorientation data (camera position and pointing), ONC orthoimages, and an ONC-based...

A thermal inertia map of the C-type Near-Earth asteroid 162173 Ryugu has been derived using the one-rotation global thermal image sets observed from the Home Position at 20 km altitude [1]. This time the thermal images of the night side areas of the surface just before sunrise were taken during observations from the dawn side. The coldest brightnes...

Using high resolution imagery from C-type asteroid Ryugu collected by MASCOT, we derive measures for surface roughness from digital image analysis.

The latitudinal dependence of regolith formation by thermal fatigue is studied for variable solar declination and surface thermal inertia. We find that regolith generation takes place in a surprisingly wide band around the equator and make predictions for the regolith distribution on the target asteroids of the upcoming Hayabusa2 and OSIRIS-REx mis...

Asteroid (162173) Ryugu is the target object of Hayabusa2, an asteroid exploration and sample return mission led by Japan Aerospace Exploration Agency (JAXA). Ground-based observations indicate that Ryugu is a C-type near-Earth asteroid with a diameter of less than 1 km, but the knowledge of its detailed properties is still very limited. This paper...

The Passive Radar Io Magma Explorer (PRIME) is a concept study to investigate the most active body in our Solar System with a low budget approach. Radar sounders have been successfully used on the Moon, on Mars and will also be represented aboard NASA’s upcoming Europa Clipper mission by REASON (Blankenship et al. 2009) and aboard ESA’s Jupiter Icy...

Asteroid (162173) Ryugu is the target object of Hayabusa2, an asteroid exploration and sample return mission led by Japan Aerospace Exploration Agency (JAXA). Ground-based observations indicate that Ryugu is a C-type near-Earth asteroid with a diameter of less than 1 km, but the knowledge of its detailed properties is still very limited. This paper...

The MASCOT radiometer MARA on board the Hayabusa2 mission will measure surface brightness temperatures on the surface of asteroid (162173) Ryugu in six wavelength bands. Here we present a method to constrain surface thermophysical properties from MARA measurements. Moreover, uncertainties when determining surface thermal inertia as well as emissivi...

By using the imagery acquired by the OSIRIS-WAC camera, we prepare a high resolution morphological map of the Rosetta Sais final landing site, characterised by an outcropping consolidated terrain unit, a coarse boulder deposit and a fine particle deposit. Thanks to the 0.014 m resolution images, we derive the pebbles/boulders size-frequency distrib...

High resolution image data of the ROLIS and OSIRIS instruments on-board the Rosetta spacecraft and its lander Philae revealed the presence of aeolian-like morphologies on the comet surface [e.g. 1, 2]. In particular, there is a set of elongated wind-tail like deposits and moat-like depressions around some larger boulders (> 5 m). Such features are...

By using the images acquired by the OSIRIS (Optical, Spectroscopic and Infrared Remote Imaging System) and ROLIS (ROsetta Lander Imaging System) cameras, we derive the size- frequency distribution (SFD) of cometary pebbles and boulders covering the size range 0.05- 30.0 m on the Agilkia landing site. The global SFD measured on OSIRIS images, reflec...

The Japanese Hayabusa-2 mission is a sample-return mission currently on its way to the C-type asteroid Ryugu. Hayabusa-2 carries the small lander MASCOT (Mobile Asteroid Surface Scout), whose scientific payload includes the infrared radiometer MARA. The primary science goal of MARA is to determine Ryugu's surface brightness temperatures at the land...

The structure of the upper layer of a comet is a product of its surface activity. The Rosetta Lander Imaging System (ROLIS) on board Philae acquired close-range images of the Agilkia site during its descent onto comet 67P/Churyumov-Gerasimenko. These images reveal a photometrically uniform surface covered by regolith composed of debris and blocks r...

ROLIS (ROsetta Lander Imaging System) [1,2] is an imager with multispectral capabilities onboard the Rosetta Lander Philae. From its location on the instruments balcony and having a down-looking orientation, ROLIS acquired an imaging sequence of the Agilkia landing site during the descent onto comet 67P/Churyumov-Gerasimenko. These images provide t...

On Nov 12, 2014, the Rosetta Philae lander descended towards comet 67P/Churyumov-Gerasimenko. The onboard ROLIS camera successfully acquired high resolution images of the surface looking down from its vantage point on the instrument platform. ROLIS is a compact CCD imager with a 1024×1024 pixel sensor and a 57 • field of view (Mottola et al., 2007,...

Introduction: ROLIS (ROsetta Lander Imaging System) [1] is an imager with multispectral capabilities onboard the Rosetta Lander Philae. From its location on the instruments balcony and having a down-looking orientation, ROLIS acquired an imaging sequence of the Agilkia landing site during the descent onto comet 67P/Churyumov-Gerasimenko. These imag...

The excited-state relaxation dynamics of a D-π-A sulfonium-based alkoxystilbene photoacid generator has been investigated in acetonitrile solution by using femtosecond transient absorption and nanosecond laser flash photolysis experiments. For the first time, the successive reaction steps involved in the photoinduced proton generation of a sulfoniu...